Ethereum

A smart contract is a computer program or a transaction protocol that is intended to automatically execute, control or document events and actions according to the terms of a contract or an agreement. The objectives of smart contracts are the reduction of need for trusted intermediators, arbitration costs, and fraud losses, as well as the reduction of malicious and accidental exceptions. Smart contracts are commonly associated with cryptocurrencies, and the smart contracts introduced by Ethereum are generally considered a fundamental building block for decentralized finance (DeFi) and NFT applications. 

Vending machines are mentioned as the oldest piece of technology equivalent to smart contract implementation. The original Ethereum white paper by Vitalik Buterin in 2014 describes the Bitcoin protocol as a weak version of the smart contract concept as originally defined by Nick Szabo, and proposed a stronger version based on the Solidity language, which is Turing complete. Since Bitcoin, various cryptocurrencies have supported programming languages which allow for more advanced smart contracts between untrusted parties. 

A smart contract should not be confused with a smart legal contract, which refers to a traditional, natural-language, legally-binding agreement that has selected terms expressed and implemented in machine-readable code. 

Etymology

Smart contracts were first proposed in the early 1990s by Nick Szabo, who coined the term, using it to refer to "a set of promises, specified in digital form, including protocols within which the parties perform on these promises". In 1998, the term was used to describe objects in rights management service layer of the system The Stanford Infobus, which was a part of Stanford Digital Library Project. 

A smart contract does not typically constitute a valid binding agreement at law, although a smart legal contract is intended to be both executable by a machine and legally enforceable. 

Smart contracts are not legal agreements, but rather means of performing obligations deriving from agreements that can be executed automatically by a computer program or a transaction protocol, such as technological means for the automation of payment obligations or obligations consisting in the transfer of tokens or cryptocurrencies. Some scholars have argued that the imperative or declarative nature of programming languages would impact the legal validity of smart contracts. 

Since the 2015 launch of the Ethereum blockchain, the term "smart contract" has been more specifically applied toward the notion of general purpose computation that takes place on a blockchain or distributed ledger. The US National Institute of Standards and Technology describes a "smart contract" as a "collection of code and data (sometimes referred to as functions and state) that is deployed using cryptographically signed transactions on the blockchain network". In this interpretation, used for example by the Ethereum Foundation or IBM, a smart contract is not necessarily related to the classical concept of a contract, but can be any kind of computer program. A smart contract also can be regarded as a secured stored procedure, as its execution and codified effects (like the transfer of value between parties) are strictly enforced and cannot be manipulated; after a transaction with specific contract details is stored into a blockchain or distributed ledger, it cannot be changed. That's because the actual execution of contracts is controlled and audited by the platform, not by arbitrary server-side programs connecting to the platform. 

In 2017, by implementing the Decree on Development of Digital Economy, Belarus has become the first-ever  country to legalize smart contracts. Belarusian lawyer Denis Aleinikov is considered to be the author of a smart contract legal concept introduced by the decree. 

In 2018, a US Senate report said: "While smart contracts might sound new, the concept is rooted in basic contract law. Usually, the judicial system adjudicates contractual disputes and enforces terms, but it is also common to have another arbitration method, especially for international transactions. With smart contracts, a program enforces the contract built into the code." A number of states in the US have passed legislation on the use of smart contracts, such as Arizona, Nevada, Tennessee, and Wyoming. And in April 2020, Iowa's House of Representatives passed a bill legally recognizing smart contracts in the state. 

In April 2021, the UK Jurisdiction Taskforce (UKJT) published the Digital Dispute Resolution Rules (the Digital DR Rules) to help enable the rapid resolution of blockchain and crypto legal disputes in Britain. 

Workings

Similar to a transfer of value on a blockchain, deployment of a smart contract on a blockchain occurs by sending a transaction from a wallet for the blockchain. The transaction includes the compiled code for the smart contract as well as a special receiver address. That transaction must then be included in a block that is added to the blockchain, at which point the smart contract's code will execute to establish the initial state of the smart contract. Byzantine fault-tolerant algorithms secure the smart contract in a decentralized way from attempts to tamper with it. Once a smart contract is deployed, it cannot be updated. Smart contracts on a blockchain can store arbitrary state and execute arbitrary computations. End clients interact with a smart contract through transactions. Such transactions with a smart contract can invoke other smart contracts. These transactions might result in changing the state and sending coins from one smart contract to another or from one account to another. 

The most popular blockchain for running smart contracts is Ethereum. On Ethereum, smart contracts are typically written in a Turing-complete programming language called Solidity, and compiled into low-level bytecode to be executed by the Ethereum Virtual Machine. Due to the halting problem and other security problems, Turing-completeness is considered to be a risk and is deliberately avoided by languages like Vyper. Some of the other smart contract programming languages missing Turing-completeness are Simplicity, Scilla, Ivy and Bitcoin Script. However, measurements in 2020 using regular expressions showed that only 35.3% of 53,757 Ethereum smart contracts at that time included recursions and loops — constructs connected to the halting problem. 

Several languages are designed to enable formal verification: Bamboo, IELE, Simplicity, Michelson (can be verified with Coq), Liquidity (compiles to Michelson), Scilla, DAML and Pact. 

Notable examples of blockchain platforms supporting smart contracts include the following:

Name Description

Ethereum Implements a Turing-complete language on its blockchain, a prominent smart contract framework 

Bitcoin Provides a Turing-incomplete script language that allows the creation of custom smart contracts on top of Bitcoin like multisignature accounts, payment channels, escrows, time locks, atomic cross-chain trading, oracles, or multi-party lottery with no operator. 

Binance Smart Chain A blockchain platform for smart contracts

Cardano A blockchain platform for smart contracts, using proof of stake

Solana A blockchain platform for smart contracts

Avalanche A blockchain platform for smart contracts

Tron A blockchain platform for smart contracts

EOS.IO A blockchain platform for smart contracts

Tezos A blockchain platform modifying its own set of rules with minimal disruption to the network through an on-chain governance model

Processes on a blockchain are generally deterministic in order to ensure Byzantine fault-tolerance. Nevertheless, real world application of smart contracts, such as lotteries and casinos, require secure randomness. In fact, blockchain technology reduces the costs for conducting of a lottery and is therefore beneficial for the participants. Randomness on blockchain can be implemented by using block hashes or timestamps, oracles, commitment schemes, special smart contracts like RANDAO and Quanta, as well as sequences from mixed strategy Nash equilibria. 

Applications

In 1998, Szabo proposed that smart contract infrastructure can be implemented by replicated asset registries and contract execution using cryptographic hash chains and Byzantine fault-tolerant replication. Askemos implemented this approach in 2002 using Scheme (later adding SQLite ) as the contract script language. 

One proposal for using bitcoin for replicated asset registration and contract execution is called "colored coins". Replicated titles for potentially arbitrary forms of property, along with replicated contract execution, are implemented in different projects.

As of 2015, UBS was experimenting with "smart bonds" that use the bitcoin blockchain in which payment streams could hypothetically be fully automated, creating a self-paying instrument. 

Inheritance wishes could hypothetically be implemented automatically upon registration of a death certificate by means of smart contracts. Birth certificates can also work together with smart contracts. 

Chris Snook of Inc.com suggests smart contracts could also be used to handle real estate transactions and could be used in the field of title records and in the public register. 

Seth Oranburg and Liya Palagashvili argue that smart contracts could also be used in employment contracts, especially temporary employment contracts, which according to them would benefit the employer. 

Smart contract on block chain technology for smart villages 

Security issues

The transactions data from a blockchain-based smart contract is visible to all users in the blockchain. The data provides cryptographic view of the transactions, however, this leads to a situation where bugs, including security holes, are visible to all yet may not be quickly fixed. Such an attack, difficult to fix quickly, was successfully executed on The DAO in June 2016, draining approximately US$50 million worth of Ether at the time, while developers attempted to come to a solution that would gain consensus. The DAO program had a time delay in place before the hacker could remove the funds; a hard fork of the Ethereum software was done to claw back the funds from the attacker before the time limit expired. Other high-profile attacks include the Parity multisignature wallet attacks, and an integer underflow/overflow attack (2018), totaling over US$184 million. 

Issues in Ethereum smart contracts, in particular, include ambiguities and easy-but-insecure constructs in its contract language Solidity, compiler bugs, Ethereum Virtual Machine bugs, attacks on the blockchain network, the immutability of bugs and that there is no central source documenting known vulnerabilities, attacks and problematic constructs. 

Difference from smart legal contracts

Smart legal contracts are distinct from smart contracts. As mentioned above, a smart contract is not necessarily legally enforceable as a contract. On the other hand, a smart legal contract has all the elements of a legally enforceable contract in the jurisdiction in which it can be enforced and it can be enforced by a court or tribunal. Therefore, while every smart legal contract will contain some elements of a smart contract, not every smart contract will be a smart legal contract. 

There is no formal definition of a smart legal contract in the legal industry. 

A Ricardian contract is a type of smart legal contract.

A decentralised application (DApp, dApp, Dapp, or dapp) is an application that can operate autonomously, typically through the use of smart contracts, that run on a decentralized computing, blockchain or other distributed ledger system. Like traditional applications, DApps provide some function or utility to its users. However, unlike traditional applications, DApps operate without human intervention and are not owned by any one entity, rather DApps distribute tokens that represent ownership. These tokens are distributed according to a programmed algorithm to the users of the system, diluting ownership and control of the DApp. Without any one entity controlling the system, the application is therefore decentralised.

Decentralised applications have been popularised by distributed ledger technologies (DLT), such as the Ethereum or Cardano blockchain, on which DApps are built, amongst other public blockchains. 

The trustless and transparent nature of DApps have led to greater developments in the utilisation of these features within the decentralized finance (DeFi) space. 

DApps are divided into numerous categories: exchanges, games, finance, gambling, development, storage, high-risk, wallet, governance, property, identity, media, social, security, energy, insurance, health, etc. 

Definition

There are a series of criteria that must be met in order for an application to be considered a DApp.

Traditional definitions of a decentralised application require a DApp to be open-source. That is, the application operates autonomously without a centralised entity in control of the majority of the application’s associated tokens. DApps also have a public, decentralised blockchain that is used by the application to keep a cryptographic record of data, including historical transactions. 

Although traditional DApps are typically open-source, DApps that are fully closed-source and partially closed-source have emerged as the cryptocurrency industry evolves. As of 2019, only 15.7% of DApps are fully open-source while 25% of DApps are closed source. In other words, the proportion of DApps with publicly available code is less than the proportion of Dapps without publicly available code. DApps that are open-source generally have higher transaction volumes than closed-source DApps. 

Secondly, tokens, required for application use and user rewards must be generated by the application as per a programmed algorithm or criteria. A portion of the application’s tokens is typically distributed at the beginning of the application’s operation. 

Lastly, the protocols of the application must be able to adapt in favor of majority consensus by the application’s users, such to make improvements to the application based on market feedback. 

Bitcoin as a DApp

Bitcoin, the first cryptocurrency, is an example of a DApp. 

Bitcoin is open-source. All transactions on the Bitcoin blockchain are open, public, immutable, and operates without the control of any centralized entity. This means every Bitcoin transaction since the beginning can be seen by everyone. Bitcoin generates its own Bitcoin tokens, through block rewards to miners for securing the network. Block rewards are halved every 210,000 blocks mined, or roughly every four years, to limit the inflationary effects on Bitcoin; thus, capping the number of total Bitcoins at 21 million. Changes to Bitcoin must be made through Bitcoin’s proof-of-work mechanism which can only be done by majority consensus of Bitcoin’s users. 

Classification

DApps can be classified based on whether they operate on their own block chain, or whether they operate on the block chain of another DApp. By this classification, DApps are divided into three types. 

Type I DApps operate on their own block chain. Block chains such as Bitcoin and Ethereum can be classified as Type I DApps. 

Type II DApps are protocols that operate on the block chain of a Type I DApp. These protocols themselves have tokens that are required for their function. 

Type III DApps are protocols that operate using the protocols of a Type II DApp. Similar to Type II DApps, Type III DApps also have tokens that are required for their function. 

Smart contracts

Smart contracts are used by developers to maintain data on the block chain and to execute operations. Multiple smart contracts can be developed for a single DApp to handle more complex operations. Over 75% of DApps are supported by a single smart contract, with the remainder using multiple smart contracts. 

DApps incur gas, that is fees paid to the validators of the block chain, due to the cost of deploying and executing the DApp's smart contracts. The amount of gas required of a DApp's functions is dependent on the complexity of its smart contracts. A complex smart contract of a DApp that operates on the Ethereum blockchain may fail to be deployed if it costs too much gas, leading to lower throughput and longer wait times for execution. 

Operation

Consensus mechanisms are used by DApps to establish consensus on the network. The two most common mechanisms to establish consensus are proof-of-work (POW) and proof-of-stake (POS). 

Proof-of-work utilises computational power to establish consensus through the process of mining. Bitcoin uses the proof-of-work mechanism. Proof-of-stake is a consensus mechanism that supports DApps through validators that secure the network by having a stake and percent ownership over the application. 

DApps distribute their tokens through three main mechanisms: mining, fund-raising and development. In mining, tokens are distributed as per a predetermined algorithm as rewards to miners that secure the network through transaction verification. Tokens can also be distributed through fundraising, whereby tokens are distributed in exchange for funding in the initial development phase of the DApp, as in an initial coin offering. Lastly, the development mechanism distributes tokens that are set aside for the purpose of developing the DApp through a pre-determined schedule. 

There are three main steps that always occur in the formation and development of any DApp: the publishing of the DApp’s whitepaper, the distribution of initial tokens, and the distribution of ownership. Firstly, the whitepaper is published, describing the DApp’s protocols, features and implementation. Then, required software and scripts are made available to the miners and stakeholders that support the validation and fundraising of the network. In exchange, they are rewarded with the initial tokens distributed by the system. Lastly, as greater numbers of participants join the network, either through utilisation of the DApp or through contributions to the DApp’s development, token ownership dilutes, and the system becomes less centralised. 

Characteristics

DApps have their backend code running on a decentralized peer-to-peer network, as opposed to typical applications where the backend code is running on centralized servers. A DApp can have frontend code and user interfaces written in any language that can make calls to its backend.

DApps have been utilized in decentralized finance (DeFi), in which dapps perform financial functions on blockchains. Decentralized finance validating peer-to-peer transactions to disrupt centralized finance and lower the cost. 

All the DApps have an identifying code that may only work on a specific platform. Not all DApps work on standard web browsers. Some of them only work on special websites with a customized code, adjusted to open certain DApps. 

The performance of a DApp is tied to its latency, throughput, and sequential performance. Bitcoin's system for transaction validation is designed so that the average time for a Bitcoin to be mined is 10 minutes. Ethereum offers a reduced latency of one transaction every 15 seconds. For comparison, Visa handles approximately 10,000 transactions per second. More recent DApp projects, such as Solana, have attempted to exceed that rate. 

Internet connectivity is a core dependency of blockchain systems, which includes DApps. High monetary costs also act as a barrier. Transactions of small monetary values can comprises a large proportion of the transferred amount. Greater demand for the service also leads to increased fees due to increased network traffic. This is an issue for Ethereum, which is attributed to increased network traffic caused by DApps built on the Ethereum blockchain, such as those used by Non-fungible tokens (NFTs). Transaction fees are affected by the complexity of a DApp's smart contracts, and by the particular blockchain. 

Trends

Ethereum is the distributed ledger technology (DLT) that has the largest DApp market. The first DApp on the Ethereum blockchain was published on April 22, 2016. From May 2017, the number of DApps being developed have grown at a higher rate. After February 2018, DApps have been published every day. Less than one fifth of DApps capture almost all the DApp users on the Ethereum blockchain. About 5% of DApps capture 80% of Ethereum transactions. 80% of DApps on Ethereum are used by less than 1000 users. On Ethereum, DApps that are exchanges capture 61.5% of transaction volume, finance DApps capture 25.6%, gambling DApps capture 5%, high-risk DApps capture 4.1%, and games capture 2.5%. 

DApps have not achieved wide adoption. Potential users may not have the skill or knowledge to be able to effectively analyse the differences between DApps and traditional applications, and also may not value those differences. This skill and information can be difficult to access for mainstream users. Additionally, the user experience for DApps is often poor, as they are often developed to prioritize functionality, maintenance and stability. 

Many DApps struggle to attract users, particularly in their founding stages, and even those that attract widespread initial popularity struggle to retain it.

A notable example was the DApp CryptoKitties, which heavily slowed down the Ethereum network at the height of its popularity. CryptoKitties and another similar gaming-based DApp Dice Games have failed to attract similar traction since. 

Examples

Augur – prediction market platform.

Cryptokitties – game built on Ethereum. It slowed Ethereum down due to insufficient transaction processing and exposed the scaling limitations of public blockchains. 

Stacks project – a platform for developing decentralized applications. 

Freelance – platform on smart contract.

Steemit – blogging and social media. 

Uniswap – a decentralized cryptocurrency exchange. 

niswap is a decentralized cryptocurrency exchange that uses a set of smart contracts (liquidity pools) to execute trades on its exchange. It's an open source project and falls into the category of a DeFi product (Decentralized finance) because it uses smart contracts to facilitate trades. The protocol facilitates automated transactions between cryptocurrency tokens on the Ethereum blockchain through the use of smart contracts. As of October 2020, Uniswap was estimated to be the largest decentralized exchange and the fourth-largest cryptocurrency exchange overall by daily trading volume. 

History

Uniswap was created on November 2, 2018 by Hayden Adams, a former mechanical engineer at Siemens. 

The Uniswap company received investments from business angel Ric Burton and venture capital firms, including Andreessen Horowitz, Paradigm Venture Capital, Union Square Ventures LLC and ParaFi. Uniswap’s average daily trading volume was US$220 million in October 2020. Traders and investors have utilized Uniswap because of its usage in decentralized finance (DeFi). 

Overview

Uniswap is a decentralized finance protocol that is used to exchange cryptocurrencies and tokens; it is provided on blockchain networks that run open-source software. This is in contrast to cryptocurrency exchanges that are run by centralized companies.

Changes to the protocol are voted on by the owners of a native cryptocurrency and governance token called UNI, and then implemented by a team of developers. UNI coins were initially distributed to early users of the protocol. Each Ethereum address that had interacted with Uniswap prior to September 1, 2020 received the ability to claim 400 UNI tokens (worth approximately $1,400 at the time). The market capitalization for the UNI token is over USD 6.6 billion as of February 2022. 

Protocol

Uniswap uses liquidity pools to fulfill orders instead of relying on a market maker, with an aim to create more efficient markets. Individuals and bots—termed "liquidity providers"—provide liquidity to the exchange by adding a pair of tokens to a smart contract which can be bought and sold by other users according to the constant-product rule {\displaystyle \phi (x,y)=xy}. In return, liquidity providers are given a percentage of the trading fees earned for that trading pair. For each trade, a certain amount of tokens is removed from the pool for an amount of the other token, thereby changing the price. No fees are required to list tokens which allow a large amount of Ethereum tokens to be accessible and no registration is required for users. As open-source software, Uniswap's code can also be forked to create new exchanges. 

In finance, a dark pool (also black pool) is a private forum (alternative trading system or ATS) for trading securities, derivatives, and other financial instruments. Liquidity on these markets is called dark pool liquidity. The bulk of dark pool trades represent large trades by financial institutions that are offered away from public exchanges like the New York Stock Exchange and the NASDAQ, so that such trades remain confidential and outside the purview of the general investing public. The fragmentation of electronic trading platforms has allowed dark pools to be created, and they are normally accessed through crossing networks or directly among market participants via private contractual arrangements. Generally, dark pools are not available to the public, but in some cases, they may be accessed indirectly by retail investors and traders via retail brokers.

One of the main advantages for institutional investors in using dark pools is for buying or selling large blocks of securities without showing their hand to others and thus avoiding market impact, as neither the size of the trade nor the identity are revealed until some time after the trade is filled. However, it also means that some market participants—retail investors—are disadvantaged, since they cannot see the orders before they are executed. Prices are agreed upon by participants in the dark pools, so the market is no longer transparent. 

Dark pools are heavily used in high-frequency trading, which has also led to a conflict of interest for those operating dark pools due to payment for order flow and priority access. High frequency traders may obtain information from placing orders in one dark pool that can be used on other exchanges or dark pools. Depending on the precise way in which a "dark" pool operates and interacts with other venues, it may be considered, and indeed referred to by some vendors, as a "grey" pool. 

These systems and strategies typically seek liquidity among open and closed trading venues, such as other alternative trading systems. Dark pools have grown in importance since 2007, with dozens of different pools garnering a substantial portion of U.S. equity trading. Dark pools are of various types and can execute trades in multiple ways, such as through negotiation or automatically (e.g., midpoint crosses, staggered crosses, VWAP, etc.), throughout the day or at scheduled times. 

History

The origin of dark pools date back to 1979 when financial regulation changed in the United States that allowed securities listed on a given exchange to be actively traded off the exchange in which it was listed. Known as reg 19c3 the U.S. Securities and Exchange Commission passed the regulation which would start on April 26, 1979. 

The new regulation allowed the emergence of dark pools through the 1980s that allowed investors to trade large block orders while avoiding market impact and giving up privacy. In 1986, Instinet started the first dark pool trading venue known as "After Hours Cross". However it was not until the next year that ITG created the first intraday dark pool "POSIT", both allowed large trades to be executed anonymously which was attractive to sellers of large blocks of shares. For the next 20 years trades executed on dark pools represented a small fraction of the market, between 3–5% of all trades. This was sometimes referred to as "upstairs trading". 

The next big development in dark pools came in 2007 when the SEC passed Regulation NMS (National Market System), which allowed investors to bypass public exchanges to gain price improvements. The effect of this was to attract a number of new players to the market and a large number of dark pools were created over the next 10 years. This was spurred on with the improvements of technology and increasing speed of execution as high-frequency trading took advantage of these dark pools. 

By 2012, 40% of trading volume in equities took place in dark pools (of which there were more than 50 in the US) and internalizers. Most dark pools were run by large banks like Credit Suisse and Goldman Sachs. 

Operation

Truly dark liquidity can be collected off-market in dark pools using FIX and FAST protocol based APIs. Dark pools are generally very similar to standard markets with similar order types, pricing rules and prioritization rules. However, the liquidity is deliberately not advertised—there is no market depth feed. Such markets have no need of an iceberg-order type. In addition, they prefer not to print the trades to any public data feed, or if legally required to do so, will do so with as large a delay as legally possible—all to reduce the market impact of any trade. Dark pools are often formed from brokers' order books and other off-market liquidity. When comparing pools, careful checks should be made as to how liquidity numbers were calculated—some venues count both sides of the trade, or even count liquidity that was posted but not filled. 

Dark liquidity pools offer institutional investors many of the efficiencies associated with trading on the exchanges' public limit order books but without showing their actions to others. Dark liquidity pools avoid this risk because neither the price nor the identity of the trading company is displayed. 

Dark pools are recorded to the national consolidated tape. However, they are recorded as over-the-counter transactions. Therefore, detailed information about the volumes and types of transactions is left to the crossing network to report to clients only if they desire or are contractually obliged to do so. 

Dark pools allow funds to line up and move large blocks of equities without tipping their hands as to what they are up to. Modern electronic trading platforms and the lack of human interaction have reduced the time scale on market movements. This increased responsiveness of the price of an equity to market pressures has made it more difficult to move large blocks of stock without affecting the price. Thus dark pools may protect traders from market participants who use HFT in a predatory manner. 

Dark pools are run by private brokerages which operate under fewer regulatory and public disclosure requirements than public exchanges. Tabb Group estimates trading on the dark pools accounts for 32% of trades in 2012 vs 26% in 2008. 

Iceberg orders

Some markets allow dark liquidity to be posted inside the existing limit order book alongside public liquidity, usually through the use of iceberg orders. Iceberg orders generally specify an additional "display quantity"—i.e., smaller than the overall order quantity. The order is queued along with other orders but only the display quantity is printed to the market depth. When the order reaches the front of its price queue, only the display quantity is filled before the order is automatically put at the back of the queue and must wait for its next chance to get a fill. Such orders will, therefore, get filled less quickly than the fully public equivalent, and they often carry an explicit cost penalty in the form of a larger execution cost charged by the market. Iceberg orders are not truly dark either, as the trade is usually visible after the fact in the market's public trade feed. 

Price discovery

If an asset can be traded only publicly, the standard price discovery process has the best chance of making the public price approximately "correct" or "fair". However, very few assets are in this category, since most can be traded off market without revealing the trade publicly. As long as non-public trades are only a small fraction of trading volumes, the public price might still be considered fair. However, the greater the proportion of trading volume that happens non-publicly, the less confident we can be that the public price is "fair". 

To lessen this adverse impact on price discovery, off-market venues can still report consolidated data on trades publicly. By this route, the trades occurring in dark pools can continue to contribute to price discovery, albeit with a little delay. 

Market impact

While it is safe to say that trading on a dark venue will reduce market impact, it is very unlikely to reduce it to zero. In particular the liquidity that crosses when there is a transaction has to come from somewhere—and at least some of it is likely to come from the public market, as automated broker systems intercept market-bound orders and instead cross them with the buyer/seller. This disappearance of the opposite side liquidity as it trades with the buyer/seller and leaves the market will cause impact. In addition, the order will slow down the market movement in the direction favorable to the buyer/seller and speed it up in the unfavourable direction. The market impact of the hidden liquidity is greatest when all of the public liquidity has a chance to cross with the user and least when the user is able to cross with ONLY other hidden liquidity that is also not represented on the market. In other words, the user has a tradeoff: reduce the speed of execution by crossing with only dark liquidity or increase it and increase their market impact. 

Adverse selection

One potential problem with crossing networks is the so-called winner's curse. Fulfillment of an order implies that the seller actually had more liquidity behind their order than the buyer. If the seller was making many small orders across a long period of time, this would not be relevant. However, when large volumes are being traded, it can be assumed that the other side—being even larger—has the power to cause market impact and thus push the price against the buyer. Paradoxically, the fulfillment of a large order is actually an indicator that the buyer would have benefitted from not placing the order to begin with—he or she would have been better off waiting for the seller's market impact, and then purchasing at the new price. 

Another type of adverse selection is caused on a very short-term basis by the economics of dark pools versus displayed markets. If a buy-side institution adds liquidity in the open market, a prop desk at a bank may want to take that liquidity because they have a short-term need. The prop desk would have to pay an Exchange/ECN access fee to take the liquidity in the displayed market. On the other hand, if the buy-side institution were floating their order in the prop desk's broker dark pool, then the economics make it very favorable to the prop desk—they pay little or no access fee to access their own dark pool, and the parent broker gets tape revenue for printing the trade on an exchange. For this reason, it is recommended that when entities transact in smaller sizes and do not have short-term alpha, do not add liquidity to dark pools; rather, go to the open market where the short-term adverse selection is likely to be less severe. 

Controversy

The use of dark pools for trading has also attracted controversy and regulatory action in part due to their opaque nature and conflicts of interest by the operator of the dark pool and the participants, a subject that was the focus of Flash Boys, a non-fiction book published in 2014 by Michael Lewis about high-frequency trading (HFT) in financial markets. 

Pipeline LLC controversy

Pipeline Trading Systems LLC, a company offering its services as a dark pool, contracted an affiliate that transacted the trades. In the Pipeline case, the firm attempted to provide a trading system that would protect investors from the open, public electronic marketplace. In that system, investors' orders would be made public on the consolidated tape as soon as they were announced, which traders characterized as "playing poker with your cards face up". The service Pipeline offered was to find counterparties for various trades in a private manner. The firm was subsequently investigated and sued by the U.S. Securities and Exchange Commission (SEC) for misleading its clients. Following its 2011 settlement of the SEC's claims against it, the firm rebranded itself as Aritas Securities LLC in January 2012. 

Regulatory statements

In 2009 the U.S. Securities and Exchange Commission (SEC) announced that it was proposing measures to increase the transparency of dark pools, "so investors get a clearer view of stock prices and liquidity". These requirements would involve that information about investor interest in buying or selling stock be made available to the public, instead of to only the members of a dark pools. FINRA announced in January 2013 that it will expand its monitoring of dark pools. 

Barclays lawsuit

In June 2014 the U.S. state of New York filed a lawsuit against Barclays alleging the bank defrauded and deceived investors over its dark pool. A central allegation of the suit is that Barclays misrepresented the level of aggressive HFT activity in its dark pool to other clients. The state, in its complaint, said it was being assisted by former Barclays executives and it was seeking unspecified damages. The bank's shares dropped 5% on news of the lawsuit, prompting an announcement to the London Stock Exchange by the bank saying it was taking the allegations seriously, and was cooperating with the New York attorney general. In July 2014 Barclays filed a motion for the suit to be dismissed, saying there had been no fraud, no victims and no harm to anyone. The New York Attorney General's office said it was confident the motion would not succeed. In January 2016, Barclays agreed to pay a fine of $35 million to SEC and $70 million to NYAG for its dark pool wrongdoings. 

UBS fine

In January 2015 the U.S. regulators imposed a fine on UBS Group AG’s dark pool for failing to follow rules designed to ensure stock trades are executed fairly. In ordering UBS to pay $14.4 million, including a $12 million fine that exceeds all prior penalties against an alternative trading system, the Securities and Exchange Commission flagged a series of violations from 2008 to 2012. It said UBS let customers submit orders at prices denominated in increments smaller than a penny, something SEC rules prohibit because it can be used to get a better place in line when buying or selling stock. The ability to trade in sub-penny increments also wasn’t widely disclosed to UBS customers, and was instead pitched secretly to market makers including high-frequency traders, according to the SEC. 

ITG fine

In August 2015, ITG (and its affiliate AlterNet Securities) settled with SEC for $20.3 million due to operating a secret trading desk and misusing the confidential trading information of dark pool subscribers. 

Impact to outside investors

Hypothetically, a retail "everyday" shareholder in any company could be disadvantaged if a dark pool trade is executed by a seller within the dark pool getting rid of a large number of that company's shares, which would thereby cause the price to drop.

Share trading performed on platforms available to the public usually come with functionality allowing any user to see how many "now" and "sell" orders are in the pipeline that day for any individual security on the platform (i.e. NASDAQ).

In turn, if dark pool trades were publicly viewable in the same way, a retail shareholder could prevent loss by selling at the same time, before the price went any lower (assuming that shareholder is confident the price won't go back up).

Because they are private and withheld from the public, in this way, they pose some risk for traders outside the dark pool.

Three major types of dark pools exist:

Independent companies set up to offer a unique differentiated basis for trading

Broker-owned dark pools where clients of the broker interact, most commonly with other clients of the broker (possibly including its own proprietary traders) in conditions of anonymity

Some public exchanges set up their own dark pools to allow their clients the benefits of anonymity and non-display of orders while offering an exchange "infrastructure"

Independent dark pools

Chi-X Global

Instinet

Liquidnet

NYFIX Millennium

Posit/MatchNow from Investment Technology Group (ITG)

State Street's BlockCross

RiverCross Securities

SmartPool

TORA Crosspoint

ETF One 

Codestreet Dealer Pool for Corporate Bonds 

Broker-dealer-owned dark pools

JP Morgan – JPMX

Barclays Capital – LX Liquidity Cross

BNP Paribas – BNP Paribas Internal eXchange (BIX)

BNY ConvergEx Group (an affiliate of Bank of New York Mellon)

Cantor Fitzgerald – Aqua Securities

Citadel Connect – Citadel

Citi – Citi Match, Citi Cross

Credit Agricole Cheuvreux – BLINK

Credit Suisse – CrossFinder

Deutsche Bank Global Markets – DBA (Europe), SuperX ATS (U.S.)

Fidelity – Capital Markets

GETCO – GETMatched

Goldman Sachs – SIGMA X

Knight Capital Group – Knight Link, Knight Match

Merrill Lynch – Instinct-X

Morgan Stanley – MSPOOL

Nomura – Nomura NX

UBS Investment Bank – UBS ATS, UBS MTF, UBS PIN

Societe Generale – ALPHA Y

Daiwa – DRECT

Wells Fargo Securities LLC – WELX (has since closed)

Consortium-owned dark pools

BIDS Trading – BIDS ATS

LeveL ATS

Luminex (Buyside Only)

Exchange-owned dark pools

ASX Centre Point

International Securities Exchange

NYSE Euronext

BATS Trading

Turquoise

XTX Markets

Dark pool aggregators

Fidessa – Spotlight

Bloomberg Tradebook

Liquidnet – LN Dark

Credit Suisse – Crossfinder Plus

Deutsche Bank – SuperX+

Software AG – Apama

ONEPIPE – Weeden & Co. & Pragma Financial

Xasax Corporation

Crossfire – Credit Agricole Cheuvreux

Instinet – Nighthawk

Bernstein – Shadow

Wells Fargo – Komodo Dark

Regulation

Dark pools were largely motivated by the trades of large blocks and participants who did not want to move the market and cause front running. In the United States, however, these trades were stymied by Regulation NMS in 2004. However, under section 5 of the Securities Exchange Act of 1934 and Regulation ATS of 1998, off-exchange trading was allowed for up to five percent of the national volume of a stock. 

The U.S. SEC adopted rules, as amendments to Regulation ATS, to require disclosures about dark pools in 2018. Known as Rule 304 of Regulation ATS, it requires the filing of Form ATS-N which includes a variety of disclosures including conflicts of interest, methods, fees, and so on. A review of these forms revealed a number of differences, including "tiering", "pegging", and "immediate-or-cancel (IOC)" orders, as well as a special features such as a speed bump by IEX to prevent high-frequency trading. 

FINRA reports data on ATS systems quarterly for free, which it began doing in July 2015. When FINRA released this data, it showed that trades averaged 187 shares, which suggests that the pools were not used for large trades by institutional shareholders. 

CryptoKitties is a blockchain game developed by Canadian studio Dapper Labs. The game allows players to buy, sell, and create NFTs using on Ethereum. These NFTs represent virtual cats. The game's popularity in December 2017 congested the Ethereum network, causing it to reach an all-time high in the number of transactions and slowing it down significantly. 

Dapper Labs was spun-off from Axiom Zen. Both companies are based in Vancouver, Canada. CryptoKitties is the first major game to use blockchains, and one of the earliest examples of a blockchain project designed for recreation. 

Gameplay

Players purchase, breed and trade virtual cats that have different visual features of varying levels of rarity. Players must purchase Ether cryptocurrency to join the game, and spend it to perform each breeding and trade action within the game. 

The virtual cats are breedable and carry a unique number and 256-bit distinct genome with DNA and different attributes (known as "cattributes") that can be passed to offspring. Several traits can be passed down from the parents to the offspring. There are a total of 12 cattributes for any cat, including pattern, mouth shape, fur, eye shape, base color, accent color, highlight color, eye color, and optional wild, environment, 'purrstige' and 'secret'. Other features like cool downtimes are not passed down, but are instead a function of the 'generation' of the offspring, which is one more than the 'generation' of the highest 'generation' attribute. 

A CryptoKitty does not have a permanently assigned gender. While they can only engage in one breeding session at one time, each cat is able to act as either matron or sire. There is a 'cooldown' time that indicates how soon the cat can breed again, which goes up with the number of breeds, capped at one week. 

The virtual cats are static images that can only be purchased, bred and sold. The game has no goal. 

Background

CryptoKitties operates on Ethereum's underlying blockchain network. Each CryptoKitty is a non-fungible token (NFT). Each is unique and owned by the user, validated through the blockchain, and its value can appreciate or depreciate based on the market. CryptoKitties cannot be replicated and cannot be transferred without the user's permission even by the game developers. Users can interact with their CryptoKitties, having the ability to buy, sell, and sire (breed) them. However, the CryptoKitty art is not on the blockchain and is instead owned by Axiom Zen. The company released some of the art under a new 'Nifty' license that lets players use the image of their CryptoKitty in a limited way. A test version of CryptoKitties was unveiled at ETH Waterloo on October 19, 2017, an Ethereum hackathon. As of December 2, 2017, Genesis, the first high selling cat was sold for ETH246.9255 (~US$117,712) on that day. 

On March 20, 2018, it was announced that CryptoKitties would be spun off into its own company, Dapper Labs, and raised $12 million from several top venture capital firms and angel investors. The investment round was led by New York based Union Square Ventures and San Francisco based Andreessen Horowitz. 

On May 12, 2018, a CryptoKitty was sold for $140,000. In May 2018, CryptoKitties launched their first celebrity-branded CryptoKitty with Stephen Curry, an American professional basketball player. As part of the partnership, Curry was given three CryptoKitties with special imagery, the first of which he put up for auction. The company later suspended the auction, claiming that Stephen Curry was not as involved as they initially thought. The company was later sued for trade secret theft over the Stephen Curry collectibles. The court ruled in the company's favour, stating that "the evidence demonstrates that Defendant, not Plaintiff, developed the idea to license digital collectibles using the likeness of celebrities first…". 

In October 2018, CryptoKitties reached the milestone of 1 million cats being bred with a volume of 3.2 million transactions on its smart contracts. In November 2018, Dapper Labs, which was spun out of Axiom Zen as the developer of CryptoKitties, raised an additional $15 million in a venture round led by Venrock. The company doubled its valuation in this round. 

In 2018, CryptoKitties was used by the German museum ZKM Center for Art and Media Karlsruhe to showcase blockchain technology. 

Technology

A CryptoKitty's ownership is tracked via a smart contract on the Ethereum blockchain. Each CryptoKitty is represented as a non-fungible token using the ERC-721 token standard on Ethereum. Generation 0 CryptoKitties were sold to players in an auction at the rate of one every 15 minutes (672 per week) for one year. New CryptoKitties are created by breeding existing CryptoKitties. 

Based on the limited number of cats going into circulation and their limited genomes, there is a limit of around 4 billion total cats that can be bred. Each cat has a distinct visual appearance ("phenotype") determined by its immutable genes ("genotype") stored in the smart contract. Because cats are tokens on a blockchain, they can be bought, sold, or transferred digitally, with strong guarantees of ownership. 

Axiom Zen developed the game. Until November 2018, Axiom Zen intended to continually release a new CryptoKitty every 15 minutes, with the rest of supply determined by breeding of CryptoKitties. CryptoKitty owners may put them up for sale via an auction for a price set in Ether (ETH). They could also put them up for sire, where another player can pay to breed with a specific CryptoKitty. 

Reception

Shortly after launch, there were concerns that CryptoKitties was crowding out other businesses that use the Ethereum platform. The game caused an increase in pending transactions on Ethereum, and at one point accounted for about 25% of network traffic on Ethereum. Ethereum miners increased the gas limit in response to CryptoKitties, which allowed for more data per block and increasing transactions per second. A variety of similar websites such as Etheremon, Ethertulips, and CryptoBots, were also created. Marketplace sites such as OpenSea and RareBits were created as a response. In March 2021 CryptoKitties announced plans to switch to the Flow blockchain in the "near future". 

Vitaly Dmitrievich Buterin (Russian: Вита?лий Дми?триевич Буте?рин), better known as Vitalik Buterin (Russian: Вита?лик Буте?рин, born 31 January 1994), is a Russian-Canadian computer programmer, and co-founder of Ethereum. Buterin became involved with cryptocurrency early in its inception, co-founding Bitcoin Magazine in 2011. In 2014, Buterin deployed the Ethereum blockchain with Dimitry Buterin,

 Gavin Wood, Charles Hoskinson, Anthony Di Iorio, and Joseph Lubin. 

Early life and education

Buterin was born in Kolomna, Russia, in 1994. His father Dmitry was a computer scientist. He lived in the area until the age of six, when his parents emigrated to Canada in search of better employment opportunities. While in grade three of elementary school in Canada, Buterin was placed into a class for gifted children and was drawn to mathematics, programming, and economics. Buterin then attended The Abelard School, a private high school in Toronto. Buterin learned about Bitcoin from his father, Dimitry Buterin, at the age of 17. 

After high school, Buterin attended the University of Waterloo. There, he took advanced courses and was a research assistant for cryptographer Ian Goldberg, who co-created Off-the-Record Messaging and was the former board of directors chairman of the Tor Project. In 2012, Buterin won a bronze medal in the International Olympiad in Informatics in Italy. 

In 2013, he visited developers in other countries who shared his enthusiasm for code. He returned to Toronto later that year and published a white paper proposing Ethereum. He dropped out of university in 2014 when he was awarded with a grant of $100,000 from the Thiel Fellowship, a scholarship created by venture capitalist Peter Thiel and went to work on Ethereum full-time. 

On 30 November 2018, Buterin received an honorary doctorate from the Faculty of Business and Economics of the University of Basel on the occasion of the Dies Academicus. 

In 2011, Buterin began writing for a publication called Bitcoin Weekly after meeting a person on a bitcoin forum with the aim of earning bitcoin. The owner offered five bitcoin (about $3.50 at the time) to anyone who would write an article for him. Buterin wrote for the site until it shut down soon thereafter due to insufficient revenue. In September 2011, Mihai Alisie reached out to Buterin about starting a new print publication called Bitcoin Magazine, a position which Buterin would accept as the first co-founder, and contribute to as a leading writer. 

Bitcoin Magazine in 2012 later began publishing a print edition and has been referred to as the first serious publication dedicated to cryptocurrencies. While working for Bitcoin Magazine, Buterin reached out to Jed McCaleb for a job at Ripple who accepted. However, their proposed employment fell apart after Ripple was unable to support a U.S. visa for Buterin. 

In addition, he held a position on the editorial board of Ledger in 2016, a peer-reviewed scholarly journal that publishes full-length original research articles on the subjects of cryptocurrency and blockchain technology. 

Buterin is the inventor of Ethereum, described as a "decentralised mining network and software development platform rolled into one" that facilitates the creation of new cryptocurrencies and programs that share a single blockchain (a cryptographic transaction ledger). 

Buterin first described Ethereum in a white paper in November 2013. Buterin had argued that bitcoin needed a scripting language for application development. But when he failed to gain agreement, he proposed development of a new platform with a more general scripting language. :?88?

The Ethereum white paper was circulated and interest grew in the new protocol in late 2013 and early 2014. Buterin announced Ethereum more publicly at the North American Bitcoin Conference in Miami on 26 January. Buterin delivered a 25-minute speech, describing the general-purpose global computer operating on a decentralized permissionless network, ending with potential uses for Ethereum that ranged from crop insurance to decentralized exchanges to DAOs. :?92,?110–130? 

About the Ethereum Project, Buterin said in 2020: "I am truly grateful to have the opportunity to work in such an interesting and interdisciplinary area of industry, where I have the chance to interact with cryptographers, mathematicians and economists prominent in their fields, to help build software and tools that already affect tens of thousands of people around the world, and to work on advanced problems in computer science, economics and philosophy every week." However, in a 2018 New Yorker article, his father suggests that Buterin is trying to avoid the focus on him as the philosopher king of the blockchain world, stating "He is trying to focus his time on research. He's not too excited that the community assigns so much importance to him. He wants the community to be more resilient." 

Buterin has stated that he was driven to create decentralized money because his World of Warcraft character was nerfed, specifically by patch 3.1.0. He went on to say in his about.me bio, "I happily played World of Warcraft during 2007–2010, but one day Blizzard removed the damage component from my beloved warlock’s Siphon Life spell. I cried myself to sleep, and on that day I realized what horrors centralized services can bring. I soon decided to quit." 

Open-source software

Buterin has contributed as a developer to other open-source software projects. He also contributed to DarkWallet by Cody Wilson, Bitcoin Python libraries, and the cryptocurrency marketplace site Egora. 

Ethereum Russia

As Buterin was recognizing the economic and political relevance of the Ethereum enterprise for his native Russia, he met with President Vladimir Putin on 2 June 2017, at the St. Petersburg International Economic Forum (SPIEF). Putin stated that he "supported the idea of establishing ties with possible Russian partners". 

Work with Glen Weyl

Buterin came into contact with economist Glen Weyl after tweeting about Weyl's proposal for a new wealth tax. The two then wrote a manifesto Liberation Through Radical Decentralization, where they highlighted the common ground between Buterin's work on cryptocurrencies and Weyl's work on market-based solutions to social problems. Collaborating with Zoe Hitzig, a PhD student at Harvard, they published a paper in 2019 entitled A Flexible Design for Funding Public Goods. The paper sets out a method for optimal provision of public goods, using a version of quadratic voting. As of August 2022, quadratic funding had been used to allocate over $20 million to open-source software projects, primarily through Gitcoin Grants. 

Awards and recognition

Thiel Fellowship, 2014 

World Technology Award in the IT Software category, 2014 

Fortune 40 under 40 list, 2016 

Forbes 30 under 30 list, 2018 

Fortune the ledger 40 under 40 list, 2018 

University of Basel Honorary doctorate, 2018 

Time 100, 2021 

Philanthropy

Donation of $763,970 of Ether to the Machine Intelligence Research Institute in 2017. 

Donation of $2.4 million of Ether to the SENS Research Foundation in 2018, for the research on rejuvenation biotechnologies and human life extension.  

Donation of $50,000 to the SENS Research Foundation in 2020. Together with Sam Bankman-Fried and Haseeb Qureshi, a total of $150,000 was donated the SENS Research Foundation to combat aging and aging-related diseases at the choice of users of Twitter through open voting.  

Buterin donated $1.14 billion USD worth of SHIBA coins, which had previously been gifted to him, to India's Crypto Covid relief fund in 2021. This donation was 5% of the coin in circulation and caused a 50% crash in the price at the time. 

Donation of $336 million worth of Dogelon Mars ($ELON), which had previously been gifted to him, to the Methuselah Foundation, which focuses on extending human lifespan, on 12 May 2021. Buterin's donation of the memecoin caused a 70% drop in its value. 

A philanthropist is someone who engages in philanthropy; donating their time, money, and/or reputation to charitable causes. The term may apply to any volunteer or to anyone who makes a donation, but the label is most often applied to those who donate large sums of money or who make a major impact through their volunteering, such as a trustee who manages a philanthropic organization or one who establishes and funds a foundation. 

A philanthropist may not always find universal approval for their deeds. Common accusations include supporting an unworthy cause (such as funding art instead of fighting world hunger) or having selfish motivation at heart (such as avoiding taxes or attaining personal fame). A philanthropist is also someone who cares for someone else's needs instead of their own.

Notable philanthropists

Abdul Rahman Al-Sumait – founder of Direct Aid, a charity organization. 

Abdul Sattar Edhi – co-head of the Edhi Foundation in Pakistan 

Achyuta Samanta – founder of the Kalinga Institute of Social Sciences (KISS)

Adar Poonawalla – In 2016, he was listed by GQ Magazine and awarded Philanthropist of the year. 

Ailsa Mellon-Bruce – co-founder of the Andrew W. Mellon Foundation

Alisher Usmanov – business-magnate, philanthropist, FIE President, founder of Art, science and sport foundation

Alagappa Chettiar – notable for work on Indian education

Anne-Fran?oise de Fougeret (1745-1813) – French philanthropist

Alfred Nobel – founder of the Nobel Prizes

Alicia Keys – American singer/songwriter; spokeswoman for Keep A Child Alive

Amal Hijazi – Lebanese singer, known for her philanthropy

Amjad Saqib, a Pakistani social entrepreneur, development practitioner, as well as, founder and Executive Director of Akhuwat Foundation, which is the world's largest Islamic microfinance organization that provides interest-free loans to the most deserving segments of society.

Andrew Carnegie – founder of the Carnegie Corporation of New York, Carnegie Endowment for International Peace, Carnegie Foundation for the Advancement of Teaching, Carnegie Institution for Science, Carnegie Trust for the Universities of Scotland, Carnegie Hero Fund, Carnegie United Kingdom Trust, Carnegie Council for Ethics in International Affairs, Carnegie Mellon University, and the Carnegie Museums of Pittsburgh. He also donated money to build over 2500 public libraries worldwide, the Carnegie Hall in New York, and the Peace Palace at The Hague 

Andrew Tate - Former professional kickboxer and media personality who donated $100 million dollars 

Angelina Jolie – American actress; known for her humanitarian work worldwide; a Goodwill Ambassador for the UN Refugee Agency

Annie Rensselaer Tinker - volunteer nurse in WWI and suffragist, formed the Annie R. Tinker Memorial Fund nonprofit organization 

Ansar Burney - a Pakistani human and civil rights activist and chairman of Ansar Burney Trust International

Anthony Ashley Cooper, 7th Earl of Shaftesbury – chairman of the Ragged Schools Union (during the Victorian era)

Anthony J. Drexel – founder of Drexel University

Arpad Busson – founder of Ark (Absolute Return for Kids) Academy

Audrey Geisel - Dr. Seuss's widow. President of Dr. Seuss Fund which supports a variety of causes in San Diego, including University of California, San Diego 

Azim Premji – founder of Azim Premji Foundation, donated $21 billion towards education 

Belinda Stronach – co-founder of Spread the Net

Ben Delo – took The Giving Pledge 

Bill Ackman – in 2011, the Ackmans were among The Chronicle of Philanthropy's "Philanthropy 50" list of the most generous donors 

Bill Gates – co-founder of the Bill & Melinda Gates Foundation

Bilquis Edhi – co-head of the Edhi Foundation in Pakistan

Bono – one of the world's best-known philanthropic performers; named the most politically effective celebrity of all time by the National Journal 

Calouste Gulbenkian – patron of churches, education and medicine, founder of the Calouste Gulbenkian Foundation

Cari Tuna – co-founder Good Ventures

Carlos Slim Helu – investor, telecom tycoon, founder of the Carlos Slim Foundation

Catherine T. MacArthur – co-founder of the MacArthur Foundation

Charles Garland – gave up most of his family inheritance in 1922 in order to establish the Garland Fund to promote radical charitable causes

Charles Pratt – founder of Pratt Institute

Charles Simonyi – founder of Charles and Lisa Simonyi Fund for Arts and Sciences, $100 million

Chris Hohn – Founder and Chair of The Children's Investment Fund Foundation

Chris Martin – lead singer of British alternative rock band Coldplay; known for supporting the Make Trade Fair campaign; he and his band contribute 15% of their money to charity

Christopher Reeve – founder of the Christopher and Dana Reeve Foundation

Chuck Feeney – founder of Atlantic Philanthropies

Cornelius Vanderbilt – founder of the Vanderbilt University

Cristiano Ronaldo - Professional soccer player 

Dame Shirley Porter – Tesco heiress; co-founder of The Porter Foundation; has donated to Tel Aviv University, social welfare facilities and ecological funding, the National Portrait Gallery in London

David Bohnett – founder of the David Bohnett Foundation supporting a wide range of social issues including LGBT rights

David Gilmour – singer and guitarist of Pink Floyd; was made CBE for his years of philanthropy; amongst other things, Gilmour gave $21.5 million from the auctioning of his guitars to climate change charity ClientEarth and $7.5 million from sale of his London home to the homeless charity Crisis

David Koch – founder of the David H. Koch Charitable Foundation; listed by The Chronicle of Philanthropy as one of the world's top 50 philanthropists in 2013 

Demi Lovato – provides the Lovato Treatment Scholarship; supporter of 13 different charity organization; an official Ambassador for the youth empowerment event We Day and the organization Free the Children

?or?e Vajfert – patron of humanitarian and cultural institutions and donor to the University of Belgrade

Dolly Parton – country singer; advocate for children's education through her foundation, the Imagination Library, which gives books to children to develop their reading skills before starting school. 

Don Ball – co-founder of Ballhomes, founder of Hope Center

Donald Rix – BC Innovation Council, BC Cancer Agency Foundation, BC Medical Services Foundation, and the BC Children’s Hospital Foundation

Dr. Mo Ibrahim – founder of telecom company Celtel International; set up the Mo Ibrahim Foundation to encourage better governance in Africa, and providing higher education scholarships for leadership and management for Africans; initiated the Mo Ibrahim Prize for Achievement in African Leadership

Dustin Moskovitz – co-founder Good Ventures

Edward Harkness – various private colleges and boarding schools; medical facilities; Commonwealth Fund

Elinor Sauerwein – Salvation Army philanthropist

Ellen Gates Starr – founder of the biomedical institute that bears his name Hull House

Elton John – has raised more than US$125 million just for the Elton John AIDS Foundation. In 2004 he donated over US$43 million to organizations around the world, making him the most generous person in music for that year, "a title he retains year after year." In 1997 he raised US$40 million for charity through sales of the single "Candle in the Wind 1997". He currently supports at least 57 charities. 

Enriqueta Augustina Rylands – founder of the John Rylands Library

Eric Schmidt and Wendy Schmidt: The Schmidt Family Foundation, Schmidt Ocean Institute and Schmidt Futures

Fazle Hasan Abed – founder of BRAC

Frank F Islam – information technology entrepreneur, working to improve education system. $2 million invested in Aligarh Muslim University for a separate business school. 

Gary Sinise – co-founder of Operation Iraqi Children

Gautam Adani – Adani is the owner of the Adani Foundation, funded through the Adani Group. It was founded in 1996. Other than Gujarat, the organisation operates in the states of Maharashtra, Rajasthan, Himachal Pradesh, Madhya Pradesh, Chhattisgarh, and Odisha. 

George Clooney – known for humanitarian work in aiding the Darfur conflict, organizing Hope for Haiti Now, and involvement in Not On Our Watch

George Peabody – founder of numerous charitable institutions in the United States and United Kingdom 

George Soros – estimated to have donated more than US$32 billion, often through the Open Society Institute and Soros Foundations

Godwin Maduka – doctor and founder of Las Vegas Pain Institute and Medical Center

Gerry Lenfest – donated $5 million in coherence with Chester County to preserve over 1,000 acres (4.0 km2) of land in Newlin Township, Chester County, Pennsylvania; the land is now owned by Natural Lands 

Hansj?rg Wyss – businessman, founder of a medical research and design company Synthes and the Wyss Foundation

Hasan Piker - left-wing political commentator

Henry Ford – co-founder of the Ford Foundation

Henry W. Bloch – founder of H&R Block Tax company. Henry established the nationally acclaimed Marion Bloch Neuroscience Institute, formed the Marion and Henry Bloch Family Foundation one of the largest family foundations in the region (Midwest) and many other places in the Kansas City community

Hilmar Reksten – Norwegian shipping magnate, tax evader, patron of the arts

Holden Karnofsky – co-founder and board member of the charity evaluator GiveWell and the executive director of the Open Philanthropy Project

Howard Ahmanson Jr. – multi-millionaire philanthropist and financier of the causes of many conservative Christian cultural, religious and political organizations

Howard Hughes – aviator, engineer, industrialist and film producer; donated US$1.56 billion to various charities including the Howard Hughes Medical Institute

Iain Percy – co-founder of the Andrew Simpson Sailing Foundation which was set up after the death of his best friend Andrew Simpson to facilitate children's access to sailing

Imran Khan – founder of the Shaukat Khanum Memorial Trust, which was behind the first cancer research institution in Pakistan

Irwin M. Jacobs – contributed hundreds of millions of dollars to the field of education through donations and grants to schools and organizations

Isaac Wolfson – managing director of Great Universal Stores

J. Paul Getty – funded the construction of the Getty Villa, the original Getty Museum, and donated his art collection to it; upon his death, left his fortune to the Getty Museum, which eventually expanded to the Getty Center in Los Angeles

J.K. Rowling – President of One Parent Families; advocate for social equity

James E. Stowers – founder of the Stowers Institute for Medical Research

James Packer – jointly with his majority-owned company Crown Resorts pledged $200 million over 10 years to support Australian community groups 

Jamie and Karen Phelps Moyer – founded the Moyer Foundation to assist non-profit organizations in raising money for children with serious distress

Jamsetji Tata – founded Tata Group 

Jane Addams – co-founder of the Hull House settlement house in Chicago 

Janet Lacey – English charity director of Christian Aid 

Jeff Bezos - Founder and billionaire of Amazon.com who help homeless and charity like Fred Hutchinson Cancer Research Foundation.

Jimmy Donaldson ("MrBeast"), a YouTuber and founder of Beast Philanthropy, a YouTube channel known for its charitable videos. Also collaborated in two fundraising challenge events known as Team Trees and Team Seas which aimed to raise $20 million and $30 million USD in return of planting 20 million trees and removing 30 million pounds of trash respectively.

Joe Blackman – dedicated much of his youth to helping young people start their own businesses

John Cena – Wrestler, actor, television personality, philanthropist under Make-A-Wish Foundation

John D. MacArthur – co-founder of the MacArthur Foundation

John D. Rockefeller – founder of the University of Chicago, Rockefeller University, Central Philippine University, General Education Board, and Rockefeller Foundation

John D. Rockefeller III – major third-generation Rockefeller philanthropist; founder of the Asia Society (1956), the Population Council (1952) and a reconstituted Japan Society; chairman of the Rockefeller Foundation for 20 years; established the Rockefeller Public Service Awards in 1958

John D. Rockefeller Jr. – expanded the Rockefeller Foundation and Rockefeller University; bought and then donated the land in Manhattan upon which the United Nations headquarters was built

John Harvard – one of the founders of Harvard College

John Peele Clapham (1801–1875) – founder of Salem Chapel, Burley in Wharfedale, a founder of West Park United Reformed Church, Harrogate, founder of various Sunday schools, editor of hymn book.

John R. Hunting – major contributor to liberal or progressive 527 organizations 

John Studzinski – champion of the homeless and the arts in the UK; founder and owner of the Genesis Foundation

Johns Hopkins – founder of the Johns Hopkins University and the Johns Hopkins Hospital

John Smith - British banker who paid for the building of St Matthias' Church, Burley and other causes. 

Jon Bon Jovi – American rock star; founder of The Jon Bon Jovi Soul Foundation in 2006

Joseph Rowntree – founder of the four Rowntree trusts

Joseph Vijay Chandrasekhar — Indian actor, singer and dancer known for his humanitarianism

Juana Ross Edwards (1830-1913), Chilean philanthropist

Juliette Gordon Low – founder of the Girl Scouts of the USA in 1912 in Savannah, Georgia

Julius Curtis Lewis Jr. – made an estimated lifetime donations of US$130 million to various civic, spiritual; charitable organizations, many in Savannah, Georgia

Julius Rosenwald - part-owner and leader of Sears, Roebuck, constructed over 5,000 schools for African American students during the Jim Crow era, and established the Rosenwald Fund, which donated millions of dollars in funds to African American causes

Kenneth C. Griffin – founder and CEO of Citadel LLC; co-founder of the Kenneth and Anne Griffin Foundation 

Kumar Mangalam Birla – As per the EdelGive Hurun India Philanthropy List 2021, Kumar Mangalam Birla and his family ranked fourth on the philanthropy list with donations mostly to the healthcare sector. 

Lady Gaga – founder of the Born This Way Foundation, a charity started in 2011

Larry Ellison – pledged to give more than half the value of his stock in Oracle Corporation to the Bill and Melinda Gates Foundation 

Levi Strauss – gave to many notable foundations of his time; gave to many Jewish synagogues and organizations

Lionel Messi - Professional soccer player 

Li Ka-shing – founder and chairman of the Li Ka Shing Foundation, which focuses on capacity empowerment through education and building of a caring society through medical and healthcare related projects; in 2006, pledged to donate one-third of his fortune estimated at over US$10 billion to philanthropic projects

Linus Pauling – donated time and effort and spent personal funds to bring about the worldwide ban on above-ground nuclear weapons testing

Lucia Hou – awarded the 2018 Woman of Year internationally by World Class Beauty Queen for her philanthropy work around the world

Lucy Salisbury Doolittle – American philanthropist

Luka ?elovi? – benefactor of Serbian education

Madonna – founder of Ray of Light Foundation (1998), and Raising Malawi (2006), have donated to and advocated for numerous organizations and causes

Mahesh Babu – In addition to being an actor, he is a humanitarian and philanthropist – he runs a charitable trust and non-profit organisation, Heal-a-Child. He is also associated with Rainbow Hospitals as their goodwill ambassador.

Marc Benioff – created the 1-1-1 model of integrated corporate philanthropy, by which companies contribute 1 percent of equity, 1 percent of employee hours, and 1 percent of product back to the community 

Marian Tompson – co-founder of La Leche League International, a breastfeeding support organization

Mariah Carey – Police Athletic League of New York City, Obstetrics, NewYork-Presbyterian Hospital, World Food Programme, LGBT community, America: A Tribute to Heroes, Kosovo, Live 8 concert, London, Hurricane Katrina, Just Stand Up!, Stand Up to Cancer, The Fresh Air Fund, and China Covid-19

Mark Zuckerberg – co-founder of social media network Facebook

Marija Trandafil – benefactor of education, medicine and welfare in Novi Sad

Mary Fels (1863-1953) - founder of Joseph Fels International Commission

Mary Lee Ware – principal sponsor of the Harvard Museum of Natural History's famous Glass Flowers exhibit; a key player in the creation of the New Hampshire Rhododendron State Park

Mary Louise Milliken Childs – builder of the Milliken Memorial Community House, the first privately donated community house in America

Melinda Gates – co-founder of the Bill & Melinda Gates Foundation

Metallica – All Within My Hands Foundation, dedicated to creating sustainable communities by supporting workforce education, the fight against hunger, and other critical local services. They also donate a portion of ticket sales in every city visited a local charity (predominantly food banks)

Michael Bloomberg – donations include over US$1.1 billion to Johns Hopkins University

Michael Dell – established the Michael and Susan Dell Foundation, which focuses on grants, urban education, childhood health, and family economic stability

Michael Jackson – donated more than US$500 million to various foundations and won numerous awards for his humanitarianism; founded the Heal the World Foundation 

Michelle Dilhara – Sri Lankan actress

Milton Hershey – founder of West Heath School

Mir Osman Ali Khan – the 7th Nizam of Hyderabad who donated 5000kgs of Gold to India and many donations to Temples, churches and other educations institutions. 

Mi?a Anastasijevi? – philanthropist of the 19th century Serbia

Mohammed bin Rashid Al Maktoum – founder of the Mohammed bin Rashid Global Initiatives, a grouping of some 33 charities, awards and philanthropic entities.

Mr. T – actor; motivational speaker; donated all his gold to charity

Nikola Spasi? – Serbian philanthropist.

Nita Ambani – Reliance Foundation is an Indian philanthropic initiative founded in 2010 by Nita Ambani. Reliance Industries is a patron of the organization. 

Nicholas M. Butler – president of the Carnegie Endowment for International Peace, 1925-1945

Oprah Winfrey – estimated donations above US$300 million, and founder of Oprah's Angel Network

P. K. Subban – Canadian ice hockey player; donated $10 million to the Montreal Children's Hospital

Paul Mellon – major benefactor of arts and education; co-founder of the Andrew W. Mellon Foundation

Paul Newman – founder of Newman's Own and the Hole in the Wall Gang Camp for seriously ill children; major donations to other charities

Paul Walker – founder of the charity Reach Out Worldwide

Peter Cooper – set up a free college in New York City to help poor people ambitious to improve themselves; Thomas Edison was an early alum 

Petra N?mcov? – Czech supermodel; founder of the Happy Hearts Fund

Phil Knight – co-founder of Nike, Inc.; supporter of Oregon Health & Science University, Stanford University and the University of Oregon

Prince Al-Waleed bin Talal – chairman of investment firm Kingdom Holding Company; pledged US$32bn donation to his philanthropy organization Alwaleed Philanthropies 

Prince Karim Aga Khan IV – founder and chairman of the Aga Khan Development Network which focuses on health, education, culture, rural development, institution-building and the promotion of economic development 

Princess Bernice Pauahi – left properties to the education of Hawaiian boys and girls in what is now Kamehameha Schools

Ramzan Chhipa, a Pakistani philanthropist and social worker and Chairman of Chhipa Welfare Association based in Karachi, Pakistan

Ratan Tata – founder of Sir Ratan Tata Trust and chairman of Tata Trust 

Raymond and Ruth Perelman – parents of Ronald O. Perelman; in 2011 donated $225 million to the University of Pennsylvania Medical School, the largest donation in that university's history

Richard Desmond – President of the Norwood Charity; raised around ?14m for charitable causes with the RD Crusaders; helped build the Richard Desmond Children's Eye Centre part of Moorfields Eye Hospital

Richard Ellis (mayor) – self-made man and property developer, who gifted his town its Jubilee Memorial and paid for other town needs. 

Rizwan Hussain – barrister, television presenter, international humanitarian worker; former Hindi music singer and producer; known for presenting Islamic and charity shows on Channel S and Islam Channel 

Robert Bass – large donations with wife Ann to Yale University, including the building of the Bass Library at Yale, and numerous other groups including the Brookings Institution, Duke University and Stanford University where Mr. Bass is on the board of trustees.

Rohini Nilekani – Nilekani is also a philanthropist and pledged ?50 crores to Ashoka Trust for Research in Ecology and the Environment (ATREE). 

Ronald O. Perelman – largest Revlon stockholder; has donated over $200 million to various causes since 2001, including a $50 million gift to create the Ronald O. Perelman Heart Institute at New York-Presbyterian Hospital and Weill Cornell Medical Center; signed the Gates-Buffett Pledge in August 2010, committing up to half his assets to be designated for the benefit of charitable causes (after his family and children have been provided for) 

Ruth Pfau – head of the Marie Adelaide Leprosy Centre in Pakistan; as a result of her efforts, the World Health Organization declared leprosy a controlled disease in Pakistan in 1996

Sainsbury family – founders of Sainsbury's, the UK's large supermarket chain and the Sainsbury Family Charitable Trusts

Samuel Morley MP – founded Morley College, London; endowed other institutions and causes

Sava Tekelija – benefactor of scientific education

Sean Parker – donated $600 million to launch the Parker Foundation, which focuses on three areas: Life Sciences, Global Public Health and Civic Engagement; and donated $250 million to create the Parker Institute for Cancer Immunotherapy

Shah Rukh Khan – the only Indian to receive UNESCO Pyramide con Marni award for his charity work in 2011

Shakira – founder of Pies Descalzos Foundation

Sheema Kermani, a Pakistani social activist (Culture, Women's rights, Peace), the founder of Tehrik-e-Niswan Cultural Action Group (Women's Movement)

Shiv Nadar – Shiv Nadar has committed more than $1 billion to philanthropy. 

Sidney Myer – founder of the Australian Department store chain Myer

Sir Charles Henry de Soysa – Ceylonese entrepreneur who pioneered a multitude of medical, educational, religious and infrastructure projects

Steve Shirley- IT entrepreneur, autism venture philanthropist, founding funder Oxford Internet Institute, UK National Ambassador for Philanthropy 2009/10

Sir Cliff Richard – one of the vice-presidents of Tearfund, a British religious, relief and development agency; supports The Hunger Project, Kidney Research UK, Roy Castle Lung Cancer Foundation, Teenage Cancer Trust, Cliff Richard Tennis Foundation, Alzheimer's Research UK; opened two new purpose-built buildings for Self Unlimited, a national charity for people with learning disabilities

Sir David Robinson – founder of the Robinson Charitable Trust and Robinson College

Sir Ganesh Dutt – longest-serving minister in British Empire who gave all his earnings to charitable works, especially education

Sir Run Run Shaw – founder of the Shaw Prize Foundation

Stanoje Petrovi? – helped fund churches in Serbia.

Stephan Schmidheiny – investor, philanthropist and advocate of sustainable development, founder of non-profits Viva Trust and Fundaci?n Avina

Steve Wozniak – provided the money, and some technical support, for technology program for the Los Gatos School district; co-founder of Apple Computer (now Apple Inc.)

Sudha Murthy – Murty's Infosys Foundation is a public charitable trust founded in 1996

Sunil Bharti Mittal – set up Bharti Foundation which runs schools for 30,000 underprivileged children in rural India

Suriya – Suriya and his family has also extended help towards the education of Sri Lankan Tamil children on behalf of the Sivakumar Charitable Trust. He is also an active participant in other humanitarian works such as "Save The Tigers" campaign, which aids in the protection and preservation of Tigers in India, and "REACH", a non-profit that cures TB patients for free using supervised medication programs. The actor celebrates every birthday by doing charity work across Tamil Nadu. 

Tarek Ben Halim – investment banker and founder of Alfanar in 2004, the first Venture philanthropy organization with a special focus on the Arab world

Thomas Holloway – Victorian patent medicine entrepreneur and founder of Royal Holloway, University of London

Ty Pennington – host of ABC's Extreme Makeover: Home Edition; advocate of doing good towards others in need and to those who give of themselves for the sake of others

Usher Raymond – American singer/songwriter; founding Chairman of the New Look Foundation; advocate for social justice

Vernon Hill – founder of Commerce Bank and President of Metro Bank; donated $10m to the Penns School of Veterinary Medicine 

Vijay Eswaran – founder of RYTHM foundation and Q NET

Virginia Weiffenbach Kettering – Dayton, Ohio's leading philanthropist and patron of the arts

Vitalik Buterin - co-founder of Ethereum. On 12 May 2021, he donated $1 billion worth of the cryptocurrencies Shiba Inu and Ether to a COVID-19 relief fund in India. 

Wallace Rasmussen – American philanthropist and proponent of higher education

Warren Buffett – pledged US$30.7 billion worth of Berkshire Hathaway stock to the Bill and Melinda Gates Foundation

Werner Reinhart – industrialist, philanthropist, music and literature patron

Weston family – founders of Loblaw food and drug retailer, a real estate investment trust Choice, Weston Foods and Weston Family Foundation

William Allen – founded and endowed many institutions and causes including 'Schools of Industry' at Lindfield and Newington Academy for Girls

William Gott – British industrialist and benefactor to churches, museums and civic buildings

William Henry Vanderbilt – co-founder of the Metropolitan Opera

William Morris, 1st Viscount Nuffield – donor of 1,700 Both respirators to hospitals, founder of the Nuffield Foundation and Nuffield College, Oxford

William Wilberforce – English politician; headed successful parliamentary campaign against the British slave trade; later supported the campaign for complete abolition

Yusuf Islam (also known as Cat Stevens) – founder of Islamic schools, Muslim Aid and Small Kindness

Zerbanoo Gifford – Founder of the ASHA Foundation. President of the World Zoroastrian Organisation.

Greatest philanthropists by amount of USD

The following table orders the greatest philanthropists by the estimated amount given to charity, corresponding to USD.

Name Amount given Cause

Jamsetji Tata $102.4 billion Education, healthcare

Bill Gates $75.8 billion Healthcare, extreme poverty, education, access to information technology

Warren Buffett $32.1 billion Healthcare, education, AIDS-prevention, sanitation

George Soros $32 billion Healthcare, anti-fascist publications, human rights, economic, legal, and social reform

Azim Premji $21 billion Education, healthcare

MacKenzie Scott $14 billion Racial equality, LGBTQ+ equality, functional democracy, and climate change 

Michael Bloomberg $12.7 billion

Environment, public health, arts, government innovation and education

Li Ka-shing $10.7 billion

Education, healthcare

Andrew Carnegie $9.5 billion

Libraries, education, peace

Elon Musk $7.6 billion Science education, COVID-19 relief, renewable energy

Chuck Feeney $6.8 billion

Healthcare, youth, ageing, poverty, human rights

Alisher Usmanov $5.8 billion Art, science, sport, healthcare

The Sainsbury family $5 billion Art, education, human rights, youth, ageing

Christopher Hohn $4.5 billion Youth, poverty, education

Carlos Slim Helu $4.2 billion Arts, education, healthcare, sports, downtown restoration

Alwaleed Philanthropies $4 billion Alwaleed Philanthropies collaborates with a range of philanthropic, government and educational organizations to combat poverty, empower women and youth, develop communities, provide disaster relief and create cultural understanding through education.

The Weston family $2.3 billion Innovations, healthcare, ageing, environment

Phil Knight $2 billion Education, healthcare, intercollegiate athletics

James E. Stowers $2 billion Healthcare

Hansjoerg Wyss $1.9 billion Climate change, poverty

Howard Hughes $1.56 billion

Healthcare

Stephan Schmidheiny $1.5 billion Environment, sustainable development

Vitalik Buterin $1 billion Donated $1 billion worth of the cryptocurrencies Shiba Inu and Ether to a COVID-19 relief fund in India.

Bitcoin Magazine

Bitcoin Magazine is one of the original news and print magazine publishers covering Bitcoin and digital currencies. Bitcoin Magazine began publishing in 2012. It was co-founded by Vitalik Buterin, Mihai Alisie, Matthew N. Wright, Vladimir Marchenko, and Vicente S. It is currently owned and operated by BTC Inc in Nashville, Tennessee. 

History

Vitalik Buterin became interested in bitcoin in 2011, and co-founded the periodical Bitcoin Magazine with Mihai Alisie, who asked him to join. Alisie was living in Romania at the time, and Buterin was writing for a blog. Buterin's writing captured the attention of Alisie, and they subsequently decided to start the magazine. Buterin took the role of head writer as a side project while attending university. 

In 2012, Bitcoin Magazine began publishing a print edition from its base in South Korea, and has been referred to as the first serious publication dedicated to cryptocurrencies. Buterin noted he spent 10-20 hours per week writing for the publication. 

In early 2015, Bitcoin Magazine was sold to its current owners, BTC Inc. 

Bitcoin Magazine at the Smithsonian

A physical copy of a 2014 edition of Bitcoin Magazine was displayed in the Smithsonian Museum as part of the Value of Money exhibit. 

Becoming Bitcoin only

In December 2018, according to a company blog post, CEO David Bailey announced that Bitcoin Magazine "would be returning to its roots and shifting its focus to Bitcoin-related stories only." 

Bitcoin Magazine in Ukraine

In September 2021, Bitcoin Magazine announced the launch of their Eastern European bureau based in Kyiv. 

Bitcoin Magazine and the NFL

In December 2021, New England Patriots quarterback Mac Jones partnered with Bitcoin Magazine to gift both Bitcoin and Bitcoin Magazine subscriptions to his offensive line. 

The Bitcoin Conference

Bitcoin 2019

In June 2019, Bitcoin Magazine hosted Bitcoin 2019 at SVN West in San Francisco, California. 

Speakers at the conference included Edward Snowden, Cathie Wood, Max Keiser, and Tim Draper. 

Bitcoin 2020

Bitcoin 2020 was cancelled due to complications with the COVID-19 pandemic. 

Bitcoin 2021

In June 2021, Bitcoin Magazine hosted Bitcoin 2021 at the Mana Wynwood in Miami, Florida. There were approximately 12,000 attendees. 

Speakers at the conference included Jack Dorsey, Ron Paul, Kevin O'Leary, Cynthia Lummis, Tyler Winklevoss, Cameron Winklevoss, Francis Suarez, Warren Davidson, Floyd Mayweather Jr., and Tony Hawk. 

In a prerecorded speech, El Salvador President Nayib Bukele announced his plans to adopt Bitcoin as legal tender in the Central American nation. 

Cryptography, or cryptology (from Ancient Greek: ???????, romanized: krypt?s "hidden, secret"; and ??????? graphein, "to write", or -????? -logia, "study", respectively ), is the practice and study of techniques for secure communication in the presence of adversarial behavior. More generally, cryptography is about constructing and analyzing protocols that prevent third parties or the public from reading private messages. Modern cryptography exists at the intersection of the disciplines of mathematics, computer science, information security, electrical engineering, digital signal processing, physics, and others. Core concepts related to information security (data confidentiality, data integrity, authentication, and non-repudiation) are also central to cryptography. Practical applications of cryptography include electronic commerce, chip-based payment cards, digital currencies, computer passwords, and military communications.

Cryptography prior to the modern age was effectively synonymous with encryption, converting readable information (plaintext) to unintelligible nonsense text (ciphertext), which can only be read by reversing the process (decryption). The sender of an encrypted (coded) message shares the decryption (decoding) technique only with the intended recipients to preclude access from adversaries. The cryptography literature often uses the names "Alice" (or "A") for the sender, "Bob" (or "B") for the intended recipient, and "Eve" (or "E") for the eavesdropping adversary. Since the development of rotor cipher machines in World War I and the advent of computers in World War II, cryptography methods have become increasingly complex and their applications more varied.

Modern cryptography is heavily based on mathematical theory and computer science practice; cryptographic algorithms are designed around computational hardness assumptions, making such algorithms hard to break in actual practice by any adversary. While it is theoretically possible to break into a well-designed system, it is infeasible in actual practice to do so. Such schemes, if well designed, are therefore termed "computationally secure". Theoretical advances (e.g., improvements in integer factorization algorithms) and faster computing technology require these designs to be continually reevaluated and, if necessary, adapted. Information-theoretically secure schemes that provably cannot be broken even with unlimited computing power, such as the one-time pad, are much more difficult to use in practice than the best theoretically breakable but computationally secure schemes.

The growth of cryptographic technology has raised a number of legal issues in the Information Age. Cryptography's potential for use as a tool for espionage and sedition has led many governments to classify it as a weapon and to limit or even prohibit its use and export. In some jurisdictions where the use of cryptography is legal, laws permit investigators to compel the disclosure of encryption keys for documents relevant to an investigation. Cryptography also plays a major role in digital rights management and copyright infringement disputes with regard to digital media. 

Terminology

The first use of the term "cryptograph" (as opposed to "cryptogram") dates back to the 19th century—originating from "The Gold-Bug," a story by Edgar Allan Poe. 

Until modern times, cryptography referred almost exclusively to "encryption", which is the process of converting ordinary information (called plaintext) into an unintelligible form (called ciphertext). Decryption is the reverse, in other words, moving from the unintelligible ciphertext back to plaintext. A cipher (or cypher) is a pair of algorithms that carry out the encryption and the reversing decryption. The detailed operation of a cipher is controlled both by the algorithm and, in each instance, by a "key". The key is a secret (ideally known only to the communicants), usually a string of characters (ideally short so it can be remembered by the user), which is needed to decrypt the ciphertext. In formal mathematical terms, a "cryptosystem" is the ordered list of elements of finite possible plaintexts, finite possible cyphertexts, finite possible keys, and the encryption and decryption algorithms that correspond to each key. Keys are important both formally and in actual practice, as ciphers without variable keys can be trivially broken with only the knowledge of the cipher used and are therefore useless (or even counter-productive) for most purposes. Historically, ciphers were often used directly for encryption or decryption without additional procedures such as authentication or integrity checks.

There are two main types of cryptosystems: symmetric and asymmetric. In symmetric systems, the only ones known until the 1970s, the same secret key encrypts and decrypts a message. Data manipulation in symmetric systems is significantly faster than in asymmetric systems. Asymmetric systems use a "public key" to encrypt a message and a related "private key" to decrypt it. The advantage of asymmetric systems is that the public key can be freely published, allowing parties to establish secure communication without having a shared secret key. In practice, asymmetric systems are used to first exchange a secret key, and then secure communication proceeds via a more efficient symmetric system using that key. Examples of asymmetric systems include Diffie–Hellman key exchange, RSA (Rivest–Shamir–Adleman), ECC (Elliptic Curve Cryptography), and Post-quantum cryptography. Secure symmetric algorithms include the commonly used AES (Advanced Encryption Standard) which replaced the older DES (Data Encryption Standard). Insecure symmetric algorithms include children's language tangling schemes such as Pig Latin or other cant, and all historical cryptographic schemes, however seriously intended, prior to the invention of the one-time pad early in the 20th century.

In colloquial use, the term "code" is often used to mean any method of encryption or concealment of meaning. However, in cryptography, code has a more specific meaning: the replacement of a unit of plaintext (i.e., a meaningful word or phrase) with a code word (for example, "wallaby" replaces "attack at dawn"). A cypher, in contrast, is a scheme for changing or substituting an element below such a level (a letter, a syllable, or a pair of letters, etc.) in order to produce a cyphertext.

Cryptanalysis is the term used for the study of methods for obtaining the meaning of encrypted information without access to the key normally required to do so; i.e., it is the study of how to "crack" encryption algorithms or their implementations.

Some use the terms "cryptography" and "cryptology" interchangeably in English, while others (including US military practice generally) use "cryptography" to refer specifically to the use and practice of cryptographic techniques and "cryptology" to refer to the combined study of cryptography and cryptanalysis. English is more flexible than several other languages in which "cryptology" (done by cryptologists) is always used in the second sense above. RFC 2828 advises that steganography is sometimes included in cryptology. 

The study of characteristics of languages that have some application in cryptography or cryptology (e.g. frequency data, letter combinations, universal patterns, etc.) is called cryptolinguistics. Cryptolingusitics is especially used in military intelligence applications for deciphering foreign communications. 

History

Before the modern era, cryptography focused on message confidentiality (i.e., encryption)—conversion of messages from a comprehensible form into an incomprehensible one and back again at the other end, rendering it unreadable by interceptors or eavesdroppers without secret knowledge (namely the key needed for decryption of that message). Encryption attempted to ensure secrecy in communications, such as those of spies, military leaders, and diplomats. In recent decades, the field has expanded beyond confidentiality concerns to include techniques for message integrity checking, sender/receiver identity authentication, digital signatures, interactive proofs and secure computation, among others.

Classic cryptography

The main classical cipher types are transposition ciphers, which rearrange the order of letters in a message (e.g., 'hello world' becomes 'ehlol owrdl' in a trivially simple rearrangement scheme), and substitution ciphers, which systematically replace letters or groups of letters with other letters or groups of letters (e.g., 'fly at once' becomes 'gmz bu podf' by replacing each letter with the one following it in the Latin alphabet). Simple versions of either have never offered much confidentiality from enterprising opponents. An early substitution cipher was the Caesar cipher, in which each letter in the plaintext was replaced by a letter some fixed number of positions further down the alphabet. Suetonius reports that Julius Caesar used it with a shift of three to communicate with his generals. Atbash is an example of an early Hebrew cipher. The earliest known use of cryptography is some carved ciphertext on stone in Egypt (c.?1900 BCE), but this may have been done for the amusement of literate observers rather than as a way of concealing information.

The Greeks of Classical times are said to have known of ciphers (e.g., the scytale transposition cipher claimed to have been used by the Spartan military). Steganography (i.e., hiding even the existence of a message so as to keep it confidential) was also first developed in ancient times. An early example, from Herodotus, was a message tattooed on a slave's shaved head and concealed under the regrown hair. More modern examples of steganography include the use of invisible ink, microdots, and digital watermarks to conceal information.

In India, the 2000-year-old Kamasutra of V?tsy?yana speaks of two different kinds of ciphers called Kautiliyam and Mulavediya. In the Kautiliyam, the cipher letter substitutions are based on phonetic relations, such as vowels becoming consonants. In the Mulavediya, the cipher alphabet consists of pairing letters and using the reciprocal ones. 

In Sassanid Persia, there were two secret scripts, according to the Muslim author Ibn al-Nadim: the ??h-dab?r?ya (literally "King's script") which was used for official correspondence, and the r?z-sahar?ya which was used to communicate secret messages with other countries. 

David Kahn notes in The Codebreakers that modern cryptology originated among the Arabs, the first people to systematically document cryptanalytic methods. Al-Khalil (717–786) wrote the Book of Cryptographic Messages, which contains the first use of permutations and combinations to list all possible Arabic words with and without vowels. 

Ciphertexts produced by a classical cipher (and some modern ciphers) will reveal statistical information about the plaintext, and that information can often be used to break the cipher. After the discovery of frequency analysis, perhaps by the Arab mathematician and polymath Al-Kindi (also known as Alkindus) in the 9th century, nearly all such ciphers could be broken by an informed attacker. Such classical ciphers still enjoy popularity today, though mostly as puzzles (see cryptogram). Al-Kindi wrote a book on cryptography entitled Risalah fi Istikhraj al-Mu'amma (Manuscript for the Deciphering Cryptographic Messages), which described the first known use of frequency analysis cryptanalysis techniques. 

Language letter frequencies may offer little help for some extended historical encryption techniques such as homophonic cipher that tend to flatten the frequency distribution. For those ciphers, language letter group (or n-gram) frequencies may provide an attack.

Essentially all ciphers remained vulnerable to cryptanalysis using the frequency analysis technique until the development of the polyalphabetic cipher, most clearly by Leon Battista Alberti around the year 1467, though there is some indication that it was already known to Al-Kindi. Alberti's innovation was to use different ciphers (i.e., substitution alphabets) for various parts of a message (perhaps for each successive plaintext letter at the limit). He also invented what was probably the first automatic cipher device, a wheel that implemented a partial realization of his invention. In the Vigen?re cipher, a polyalphabetic cipher, encryption uses a key word, which controls letter substitution depending on which letter of the key word is used. In the mid-19th century Charles Babbage showed that the Vigen?re cipher was vulnerable to Kasiski examination, but this was first published about ten years later by Friedrich Kasiski. 

Although frequency analysis can be a powerful and general technique against many ciphers, encryption has still often been effective in practice, as many a would-be cryptanalyst was unaware of the technique. Breaking a message without using frequency analysis essentially required knowledge of the cipher used and perhaps of the key involved, thus making espionage, bribery, burglary, defection, etc., more attractive approaches to the cryptanalytically uninformed. It was finally explicitly recognized in the 19th century that secrecy of a cipher's algorithm is not a sensible nor practical safeguard of message security; in fact, it was further realized that any adequate cryptographic scheme (including ciphers) should remain secure even if the adversary fully understands the cipher algorithm itself. Security of the key used should alone be sufficient for a good cipher to maintain confidentiality under an attack. This fundamental principle was first explicitly stated in 1883 by Auguste Kerckhoffs and is generally called Kerckhoffs's Principle; alternatively and more bluntly, it was restated by Claude Shannon, the inventor of information theory and the fundamentals of theoretical cryptography, as Shannon's Maxim—'the enemy knows the system'.

Different physical devices and aids have been used to assist with ciphers. One of the earliest may have been the scytale of ancient Greece, a rod supposedly used by the Spartans as an aid for a transposition cipher. In medieval times, other aids were invented such as the cipher grille, which was also used for a kind of steganography. With the invention of polyalphabetic ciphers came more sophisticated aids such as Alberti's own cipher disk, Johannes Trithemius' tabula recta scheme, and Thomas Jefferson's wheel cypher (not publicly known, and reinvented independently by Bazeries around 1900). Many mechanical encryption/decryption devices were invented early in the 20th century, and several patented, among them rotor machines—famously including the Enigma machine used by the German government and military from the late 1920s and during World War II. The ciphers implemented by better quality examples of these machine designs brought about a substantial increase in cryptanalytic difficulty after WWI. 

Early computer-era cryptography

Cryptanalysis of the new mechanical ciphering devices proved to be both difficult and laborious. In the United Kingdom, cryptanalytic efforts at Bletchley Park during WWII spurred the development of more efficient means for carrying out repetitious tasks, such as military code breaking (decryption). This culminated in the development of the Colossus, the world's first fully electronic, digital, programmable computer, which assisted in the decryption of ciphers generated by the German Army's Lorenz SZ40/42 machine.

Extensive open academic research into cryptography is relatively recent, beginning in the mid-1970s. In the early 1970s IBM personnel designed the Data Encryption Standard (DES) algorithm that became the first federal government cryptography standard in the United States. In 1976 Whitfield Diffie and Martin Hellman published the Diffie–Hellman key exchange algorithm. In 1977 the RSA algorithm was published in Martin Gardner's Scientific American column. Since then, cryptography has become a widely used tool in communications, computer networks, and computer security generally.

Some modern cryptographic techniques can only keep their keys secret if certain mathematical problems are intractable, such as the integer factorization or the discrete logarithm problems, so there are deep connections with abstract mathematics. There are very few cryptosystems that are proven to be unconditionally secure. The one-time pad is one, and was proven to be so by Claude Shannon. There are a few important algorithms that have been proven secure under certain assumptions. For example, the infeasibility of factoring extremely large integers is the basis for believing that RSA is secure, and some other systems, but even so, proof of unbreakability is unavailable since the underlying mathematical problem remains open. In practice, these are widely used, and are believed unbreakable in practice by most competent observers. There are systems similar to RSA, such as one by Michael O. Rabin that are provably secure provided factoring n = pq is impossible; it is quite unusable in practice. The discrete logarithm problem is the basis for believing some other cryptosystems are secure, and again, there are related, less practical systems that are provably secure relative to the solvability or insolvability discrete log problem. 

As well as being aware of cryptographic history, cryptographic algorithm and system designers must also sensibly consider probable future developments while working on their designs. For instance, continuous improvements in computer processing power have increased the scope of brute-force attacks, so when specifying key lengths, the required key lengths are similarly advancing. The potential impact of quantum computing are already being considered by some cryptographic system designers developing post-quantum cryptography. The announced imminence of small implementations of these machines may be making the need for preemptive caution rather more than merely speculative. 

Modern cryptography

Prior to the early 20th century, cryptography was mainly concerned with linguistic and lexicographic patterns. Since then cryptography has broadened in scope, and now makes extensive use of mathematical subdisciplines, including information theory, computational complexity, statistics, combinatorics, abstract algebra, number theory, and finite mathematics. Cryptography is also a branch of engineering, but an unusual one since it deals with active, intelligent, and malevolent opposition; other kinds of engineering (e.g., civil or chemical engineering) need deal only with neutral natural forces. There is also active research examining the relationship between cryptographic problems and quantum physics.

Just as the development of digital computers and electronics helped in cryptanalysis, it made possible much more complex ciphers. Furthermore, computers allowed for the encryption of any kind of data representable in any binary format, unlike classical ciphers which only encrypted written language texts; this was new and significant. Computer use has thus supplanted linguistic cryptography, both for cipher design and cryptanalysis. Many computer ciphers can be characterized by their operation on binary bit sequences (sometimes in groups or blocks), unlike classical and mechanical schemes, which generally manipulate traditional characters (i.e., letters and digits) directly. However, computers have also assisted cryptanalysis, which has compensated to some extent for increased cipher complexity. Nonetheless, good modern ciphers have stayed ahead of cryptanalysis; it is typically the case that use of a quality cipher is very efficient (i.e., fast and requiring few resources, such as memory or CPU capability), while breaking it requires an effort many orders of magnitude larger, and vastly larger than that required for any classical cipher, making cryptanalysis so inefficient and impractical as to be effectively impossible.

Modern cryptography

Symmetric-key cryptography refers to encryption methods in which both the sender and receiver share the same key (or, less commonly, in which their keys are different, but related in an easily computable way). This was the only kind of encryption publicly known until June 1976. 

Symmetric key ciphers are implemented as either block ciphers or stream ciphers. A block cipher enciphers input in blocks of plaintext as opposed to individual characters, the input form used by a stream cipher.

The Data Encryption Standard (DES) and the Advanced Encryption Standard (AES) are block cipher designs that have been designated cryptography standards by the US government (though DES's designation was finally withdrawn after the AES was adopted). Despite its deprecation as an official standard, DES (especially its still-approved and much more secure triple-DES variant) remains quite popular; it is used across a wide range of applications, from ATM encryption to e-mail privacy and secure remote access. Many other block ciphers have been designed and released, with considerable variation in quality. Many, even some designed by capable practitioners, have been thoroughly broken, such as FEAL. 

Stream ciphers, in contrast to the 'block' type, create an arbitrarily long stream of key material, which is combined with the plaintext bit-by-bit or character-by-character, somewhat like the one-time pad. In a stream cipher, the output stream is created based on a hidden internal state that changes as the cipher operates. That internal state is initially set up using the secret key material. RC4 is a widely used stream cipher. Block ciphers can be used as stream ciphers by generating blocks of a keystream (in place of a Pseudorandom number generator) and applying an XOR operation to each bit of the plaintext with each bit of the keystream. 

Message authentication codes (MACs) are much like cryptographic hash functions, except that a secret key can be used to authenticate the hash value upon receipt; this additional complication blocks an attack scheme against bare digest algorithms, and so has been thought worth the effort. Cryptographic hash functions are a third type of cryptographic algorithm. They take a message of any length as input, and output a short, fixed-length hash, which can be used in (for example) a digital signature. For good hash functions, an attacker cannot find two messages that produce the same hash. MD4 is a long-used hash function that is now broken; MD5, a strengthened variant of MD4, is also widely used but broken in practice. The US National Security Agency developed the Secure Hash Algorithm series of MD5-like hash functions: SHA-0 was a flawed algorithm that the agency withdrew; SHA-1 is widely deployed and more secure than MD5, but cryptanalysts have identified attacks against it; the SHA-2 family improves on SHA-1, but is vulnerable to clashes as of 2011; and the US standards authority thought it "prudent" from a security perspective to develop a new standard to "significantly improve the robustness of NIST's overall hash algorithm toolkit." Thus, a hash function design competition was meant to select a new U.S. national standard, to be called SHA-3, by 2012. The competition ended on October 2, 2012, when the NIST announced that Keccak would be the new SHA-3 hash algorithm. Unlike block and stream ciphers that are invertible, cryptographic hash functions produce a hashed output that cannot be used to retrieve the original input data. Cryptographic hash functions are used to verify the authenticity of data retrieved from an untrusted source or to add a layer of security.

Public-key cryptography

Symmetric-key cryptosystems use the same key for encryption and decryption of a message, although a message or group of messages can have a different key than others. A significant disadvantage of symmetric ciphers is the key management necessary to use them securely. Each distinct pair of communicating parties must, ideally, share a different key, and perhaps for each ciphertext exchanged as well. The number of keys required increases as the square of the number of network members, which very quickly requires complex key management schemes to keep them all consistent and secret.

In a groundbreaking 1976 paper, Whitfield Diffie and Martin Hellman proposed the notion of public-key (also, more generally, called asymmetric key) cryptography in which two different but mathematically related keys are used—a public key and a private key. A public key system is so constructed that calculation of one key (the 'private key') is computationally infeasible from the other (the 'public key'), even though they are necessarily related. Instead, both keys are generated secretly, as an interrelated pair. The historian David Kahn described public-key cryptography as "the most revolutionary new concept in the field since polyalphabetic substitution emerged in the Renaissance". 

In public-key cryptosystems, the public key may be freely distributed, while its paired private key must remain secret. In a public-key encryption system, the public key is used for encryption, while the private or secret key is used for decryption. While Diffie and Hellman could not find such a system, they showed that public-key cryptography was indeed possible by presenting the Diffie–Hellman key exchange protocol, a solution that is now widely used in secure communications to allow two parties to secretly agree on a shared encryption key. The X.509 standard defines the most commonly used format for public key certificates. 

Diffie and Hellman's publication sparked widespread academic efforts in finding a practical public-key encryption system. This race was finally won in 1978 by Ronald Rivest, Adi Shamir, and Len Adleman, whose solution has since become known as the RSA algorithm. 

The Diffie–Hellman and RSA algorithms, in addition to being the first publicly known examples of high-quality public-key algorithms, have been among the most widely used. Other asymmetric-key algorithms include the Cramer–Shoup cryptosystem, ElGamal encryption, and various elliptic curve techniques.

A document published in 1997 by the Government Communications Headquarters (GCHQ), a British intelligence organization, revealed that cryptographers at GCHQ had anticipated several academic developments. Reportedly, around 1970, James H. Ellis had conceived the principles of asymmetric key cryptography. In 1973, Clifford Cocks invented a solution that was very similar in design rationale to RSA. In 1974, Malcolm J. Williamson is claimed to have developed the Diffie–Hellman key exchange. 

Public-key cryptography is also used for implementing digital signature schemes. A digital signature is reminiscent of an ordinary signature; they both have the characteristic of being easy for a user to produce, but difficult for anyone else to forge. Digital signatures can also be permanently tied to the content of the message being signed; they cannot then be 'moved' from one document to another, for any attempt will be detectable. In digital signature schemes, there are two algorithms: one for signing, in which a secret key is used to process the message (or a hash of the message, or both), and one for verification, in which the matching public key is used with the message to check the validity of the signature. RSA and DSA are two of the most popular digital signature schemes. Digital signatures are central to the operation of public key infrastructures and many network security schemes (e.g., SSL/TLS, many VPNs, etc.). 

Public-key algorithms are most often based on the computational complexity of "hard" problems, often from number theory. For example, the hardness of RSA is related to the integer factorization problem, while Diffie–Hellman and DSA are related to the discrete logarithm problem. The security of elliptic curve cryptography is based on number theoretic problems involving elliptic curves. Because of the difficulty of the underlying problems, most public-key algorithms involve operations such as modular multiplication and exponentiation, which are much more computationally expensive than the techniques used in most block ciphers, especially with typical key sizes. As a result, public-key cryptosystems are commonly hybrid cryptosystems, in which a fast high-quality symmetric-key encryption algorithm is used for the message itself, while the relevant symmetric key is sent with the message, but encrypted using a public-key algorithm. Similarly, hybrid signature schemes are often used, in which a cryptographic hash function is computed, and only the resulting hash is digitally signed. 

Cryptographic hash functions

Cryptographic hash functions are cryptographic algorithms that generate and use keys to encrypt data, and such functions may be viewed as keys themselves. They take a message of any length as input, and output a short, fixed-length hash, which can be used in (for example) a digital signature. For good hash functions, an attacker cannot find two messages that produce the same hash. MD4 is a long-used hash function that is now broken; MD5, a strengthened variant of MD4, is also widely used but broken in practice. The US National Security Agency developed the Secure Hash Algorithm series of MD5-like hash functions: SHA-0 was a flawed algorithm that the agency withdrew; SHA-1 is widely deployed and more secure than MD5, but cryptanalysts have identified attacks against it; the SHA-2 family improves on SHA-1, but is vulnerable to clashes as of 2011; and the US standards authority thought it "prudent" from a security perspective to develop a new standard to "significantly improve the robustness of NIST's overall hash algorithm toolkit." Thus, a hash function design competition was meant to select a new U.S. national standard, to be called SHA-3, by 2012. The competition ended on October 2, 2012, when the NIST announced that Keccak would be the new SHA-3 hash algorithm. Unlike block and stream ciphers that are invertible, cryptographic hash functions produce a hashed output that cannot be used to retrieve the original input data. Cryptographic hash functions are used to verify the authenticity of data retrieved from an untrusted source or to add a layer of security.

Cryptanalysis

The goal of cryptanalysis is to find some weakness or insecurity in a cryptographic scheme, thus permitting its subversion or evasion.

It is a common misconception that every encryption method can be broken. In connection with his WWII work at Bell Labs, Claude Shannon proved that the one-time pad cipher is unbreakable, provided the key material is truly random, never reused, kept secret from all possible attackers, and of equal or greater length than the message. Most ciphers, apart from the one-time pad, can be broken with enough computational effort by brute force attack, but the amount of effort needed may be exponentially dependent on the key size, as compared to the effort needed to make use of the cipher. In such cases, effective security could be achieved if it is proven that the effort required (i.e., "work factor", in Shannon's terms) is beyond the ability of any adversary. This means it must be shown that no efficient method (as opposed to the time-consuming brute force method) can be found to break the cipher. Since no such proof has been found to date, the one-time-pad remains the only theoretically unbreakable cipher. Although well-implemented one-time-pad encryption cannot be broken, traffic analysis is still possible.

There are a wide variety of cryptanalytic attacks, and they can be classified in any of several ways. A common distinction turns on what Eve (an attacker) knows and what capabilities are available. In a ciphertext-only attack, Eve has access only to the ciphertext (good modern cryptosystems are usually effectively immune to ciphertext-only attacks). In a known-plaintext attack, Eve has access to a ciphertext and its corresponding plaintext (or to many such pairs). In a chosen-plaintext attack, Eve may choose a plaintext and learn its corresponding ciphertext (perhaps many times); an example is gardening, used by the British during WWII. In a chosen-ciphertext attack, Eve may be able to choose ciphertexts and learn their corresponding plaintexts. Finally in a man-in-the-middle attack Eve gets in between Alice (the sender) and Bob (the recipient), accesses and modifies the traffic and then forwards it to the recipient. Also important, often overwhelmingly so, are mistakes (generally in the design or use of one of the protocols involved).

Cryptanalysis of symmetric-key ciphers typically involves looking for attacks against the block ciphers or stream ciphers that are more efficient than any attack that could be against a perfect cipher. For example, a simple brute force attack against DES requires one known plaintext and 255 decryptions, trying approximately half of the possible keys, to reach a point at which chances are better than even that the key sought will have been found. But this may not be enough assurance; a linear cryptanalysis attack against DES requires 243 known plaintexts (with their corresponding ciphertexts) and approximately 243 DES operations. This is a considerable improvement over brute force attacks.

Public-key algorithms are based on the computational difficulty of various problems. The most famous of these are the difficulty of integer factorization of semiprimes and the difficulty of calculating discrete logarithms, both of which are not yet proven to be solvable in polynomial time (P) using only a classical Turing-complete computer. Much public-key cryptanalysis concerns designing algorithms in P that can solve these problems, or using other technologies, such as quantum computers. For instance, the best-known algorithms for solving the elliptic curve-based version of discrete logarithm are much more time-consuming than the best-known algorithms for factoring, at least for problems of more or less equivalent size. Thus, to achieve an equivalent strength of encryption, techniques that depend upon the difficulty of factoring large composite numbers, such as the RSA cryptosystem, require larger keys than elliptic curve techniques. For this reason, public-key cryptosystems based on elliptic curves have become popular since their invention in the mid-1990s.

While pure cryptanalysis uses weaknesses in the algorithms themselves, other attacks on cryptosystems are based on actual use of the algorithms in real devices, and are called side-channel attacks. If a cryptanalyst has access to, for example, the amount of time the device took to encrypt a number of plaintexts or report an error in a password or PIN character, he may be able to use a timing attack to break a cipher that is otherwise resistant to analysis. An attacker might also study the pattern and length of messages to derive valuable information; this is known as traffic analysis and can be quite useful to an alert adversary. Poor administration of a cryptosystem, such as permitting too short keys, will make any system vulnerable, regardless of other virtues. Social engineering and other attacks against humans (e.g., bribery, extortion, blackmail, espionage, rubber-hose cryptanalysis or torture) are usually employed due to being more cost-effective and feasible to perform in a reasonable amount of time compared to pure cryptanalysis by a high margin.

Cryptographic primitives

Much of the theoretical work in cryptography concerns cryptographic primitives—algorithms with basic cryptographic properties—and their relationship to other cryptographic problems. More complicated cryptographic tools are then built from these basic primitives. These primitives provide fundamental properties, which are used to develop more complex tools called cryptosystems or cryptographic protocols, which guarantee one or more high-level security properties. Note, however, that the distinction between cryptographic primitives and cryptosystems, is quite arbitrary; for example, the RSA algorithm is sometimes considered a cryptosystem, and sometimes a primitive. Typical examples of cryptographic primitives include pseudorandom functions, one-way functions, etc.

Cryptosystems

One or more cryptographic primitives are often used to develop a more complex algorithm, called a cryptographic system, or cryptosystem. Cryptosystems (e.g., El-Gamal encryption) are designed to provide particular functionality (e.g., public key encryption) while guaranteeing certain security properties (e.g., chosen-plaintext attack (CPA) security in the random oracle model). Cryptosystems use the properties of the underlying cryptographic primitives to support the system's security properties. As the distinction between primitives and cryptosystems is somewhat arbitrary, a sophisticated cryptosystem can be derived from a combination of several more primitive cryptosystems. In many cases, the cryptosystem's structure involves back and forth communication among two or more parties in space (e.g., between the sender of a secure message and its receiver) or across time (e.g., cryptographically protected backup data). Such cryptosystems are sometimes called cryptographic protocols.

Some widely known cryptosystems include RSA, Schnorr signature, ElGamal encryption, and Pretty Good Privacy (PGP). More complex cryptosystems include electronic cash systems, signcryption systems, etc. Some more 'theoretical' cryptosystems include interactive proof systems, (like zero-knowledge proofs), systems for secret sharing, etc.

Lightweight cryptography

Lightweight cryptography (LWC) concerns cryptographic algorithms developed for a strictly constrained environment. The growth of Internet of Things (IoT) has spiked research into the development of lightweight algorithms that are better suited for the environment. An IoT environment requires strict constraints on power consumption, processing power, and security. Algorithms such as PRESENT, AES, and SPECK are examples of the many LWC algorithms that have been developed to achieve the standard set by the National Institute of Standards and Technology. 

General

Cryptography is widely used on the internet to help protect user-data and prevent eavesdropping. To ensure secrecy during transmission, many systems use private key cryptography to protect transmitted information. With public-key systems, one can maintain secrecy without a master key or a large number of keys. But, some algorithms like Bitlocker and Veracrypt are generally not private-public key cryptography. For example, Veracrypt uses a password hash to generate the single private key. However, it can be configured to run in public-private key systems. The C++ opensource encryption library OpenSSL provides free and opensource encryption software and tools. The most commonly used encryption cipher suit is AES, as it has hardware acceleration for all x86 based processors that has AES-NI. A close contender is ChaCha20-Poly1305, which is a stream cipher, however it is commonly used for mobile devices as they are ARM based which does not feature AES-NI instruction set extension.

Cybersecurity

Cryptography can be used to secure communications by encrypting them. Websites use encryption via HTTPS. "End-to-end" encryption, where only sender and receiver can read messages, is implemented for email in Pretty Good Privacy and for secure messaging in general in WhatsApp, Signal and Telegram. 

Operating systems use encryption to keep passwords secret, conceal parts of the system, and ensure that software updates are truly from the system maker. Instead of storing plaintext passwords, computer systems store hashes thereof; then, when a user logs in, the system passes the given password through a cryptographic hash function and compares it to the hashed value on file. In this manner, neither the system nor an attacker has at any point access to the password in plaintext. 

Encryption is sometimes used to encrypt one's entire drive. For example, University College London has implemented BitLocker (a program by Microsoft) to render drive data opaque without users logging in. 

Cryptocurrencies and cryptoeconomics

Cryptographic techniques enable cryptocurrency technologies, such as distributed ledger technologies (e.g., blockchains), which finance cryptoeconomics applications such as decentralized finance (DeFi). Key cryptographic techniques that enable cryptocurrencies and cryptoeconomics include, but are not limited to: cryptographic keys, cryptographic hash functions, asymmetric (public key) encryption, Multi-Factor Authentication (MFA), End-to-End Encryption (E2EE), and Zero Knowledge Proofs (ZKP).

Legal issues

Prohibitions

Cryptography has long been of interest to intelligence gathering and law enforcement agencies. Secret communications may be criminal or even treasonous.

 Because of its facilitation of privacy, and the diminution of privacy attendant on its prohibition, cryptography is also of considerable interest to civil rights supporters. Accordingly, there has been a history of controversial legal issues surrounding cryptography, especially since the advent of inexpensive computers has made widespread access to high-quality cryptography possible.

In some countries, even the domestic use of cryptography is, or has been, restricted. Until 1999, France significantly restricted the use of cryptography domestically, though it has since relaxed many of these rules. In China and Iran, a license is still required to use cryptography. Many countries have tight restrictions on the use of cryptography. Among the more restrictive are laws in Belarus, Kazakhstan, Mongolia, Pakistan, Singapore, Tunisia, and Vietnam. 

In the United States, cryptography is legal for domestic use, but there has been much conflict over legal issues related to cryptography. One particularly important issue has been the export of cryptography and cryptographic software and hardware. Probably because of the importance of cryptanalysis in World War II and an expectation that cryptography would continue to be important for national security, many Western governments have, at some point, strictly regulated export of cryptography. After World War II, it was illegal in the US to sell or distribute encryption technology overseas; in fact, encryption was designated as auxiliary military equipment and put on the United States Munitions List. Until the development of the personal computer, asymmetric key algorithms (i.e., public key techniques), and the Internet, this was not especially problematic. However, as the Internet grew and computers became more widely available, high-quality encryption techniques became well known around the globe.

Export controls

In the 1990s, there were several challenges to US export regulation of cryptography. After the source code for Philip Zimmermann's Pretty Good Privacy (PGP) encryption program found its way onto the Internet in June 1991, a complaint by RSA Security (then called RSA Data Security, Inc.) resulted in a lengthy criminal investigation of Zimmermann by the US Customs Service and the FBI, though no charges were ever filed. Daniel J. Bernstein, then a graduate student at UC Berkeley, brought a lawsuit against the US government challenging some aspects of the restrictions based on free speech grounds. The 1995 case Bernstein v. United States ultimately resulted in a 1999 decision that printed source code for cryptographic algorithms and systems was protected as free speech by the United States Constitution. 

In 1996, thirty-nine countries signed the Wassenaar Arrangement, an arms control treaty that deals with the export of arms and "dual-use" technologies such as cryptography. The treaty stipulated that the use of cryptography with short key-lengths (56-bit for symmetric encryption, 512-bit for RSA) would no longer be export-controlled. Cryptography exports from the US became less strictly regulated as a consequence of a major relaxation in 2000; there are no longer very many restrictions on key sizes in US-exported mass-market software. Since this relaxation in US export restrictions, and because most personal computers connected to the Internet include US-sourced web browsers such as Firefox or Internet Explorer, almost every Internet user worldwide has potential access to quality cryptography via their browsers (e.g., via Transport Layer Security). The Mozilla Thunderbird and Microsoft Outlook E-mail client programs similarly can transmit and receive emails via TLS, and can send and receive email encrypted with S/MIME. Many Internet users do not realize that their basic application software contains such extensive cryptosystems. These browsers and email programs are so ubiquitous that even governments whose intent is to regulate civilian use of cryptography generally do not find it practical to do much to control distribution or use of cryptography of this quality, so even when such laws are in force, actual enforcement is often effectively impossible.

NSA involvement

Another contentious issue connected to cryptography in the United States is the influence of the National Security Agency on cipher development and policy. The NSA was involved with the design of DES during its development at IBM and its consideration by the National Bureau of Standards as a possible Federal Standard for cryptography. DES was designed to be resistant to differential cryptanalysis, a powerful and general cryptanalytic technique known to the NSA and IBM, that became publicly known only when it was rediscovered in the late 1980s. According to Steven Levy, IBM discovered differential cryptanalysis, but kept the technique secret at the NSA's request. The technique became publicly known only when Biham and Shamir re-discovered and announced it some years later. The entire affair illustrates the difficulty of determining what resources and knowledge an attacker might actually have.

Another instance of the NSA's involvement was the 1993 Clipper chip affair, an encryption microchip intended to be part of the Capstone cryptography-control initiative. Clipper was widely criticized by cryptographers for two reasons. The cipher algorithm (called Skipjack) was then classified (declassified in 1998, long after the Clipper initiative lapsed). The classified cipher caused concerns that the NSA had deliberately made the cipher weak in order to assist its intelligence efforts. The whole initiative was also criticized based on its violation of Kerckhoffs's Principle, as the scheme included a special escrow key held by the government for use by law enforcement (i.e. wiretapping). 

Digital rights management

Cryptography is central to digital rights management (DRM), a group of techniques for technologically controlling use of copyrighted material, being widely implemented and deployed at the behest of some copyright holders. In 1998, U.S. President Bill Clinton signed the Digital Millennium Copyright Act (DMCA), which criminalized all production, dissemination, and use of certain cryptanalytic techniques and technology (now known or later discovered); specifically, those that could be used to circumvent DRM technological schemes. This had a noticeable impact on the cryptography research community since an argument can be made that any cryptanalytic research violated the DMCA. Similar statutes have since been enacted in several countries and regions, including the implementation in the EU Copyright Directive. Similar restrictions are called for by treaties signed by World Intellectual Property Organization member-states.

The United States Department of Justice and FBI have not enforced the DMCA as rigorously as had been feared by some, but the law, nonetheless, remains a controversial one. Niels Ferguson, a well-respected cryptography researcher, has publicly stated that he will not release some of his research into an Intel security design for fear of prosecution under the DMCA. Cryptologist Bruce Schneier has argued that the DMCA encourages vendor lock-in, while inhibiting actual measures toward cyber-security. Both Alan Cox (longtime Linux kernel developer) and Edward Felten (and some of his students at Princeton) have encountered problems related to the Act. Dmitry Sklyarov was arrested during a visit to the US from Russia, and jailed for five months pending trial for alleged violations of the DMCA arising from work he had done in Russia, where the work was legal. In 2007, the cryptographic keys responsible for Blu-ray and HD DVD content scrambling were discovered and released onto the Internet. In both cases, the Motion Picture Association of America sent out numerous DMCA takedown notices, and there was a massive Internet backlash triggered by the perceived impact of such notices on fair use and free speech.

Forced disclosure of encryption keys

In the United Kingdom, the Regulation of Investigatory Powers Act gives UK police the powers to force suspects to decrypt files or hand over passwords that protect encryption keys. Failure to comply is an offense in its own right, punishable on conviction by a two-year jail sentence or up to five years in cases involving national security. Successful prosecutions have occurred under the Act; the first, in 2009, resulted in a term of 13 months' imprisonment. Similar forced disclosure laws in Australia, Finland, France, and India compel individual suspects under investigation to hand over encryption keys or passwords during a criminal investigation.

In the United States, the federal criminal case of United States v. Fricosu addressed whether a search warrant can compel a person to reveal an encryption passphrase or password. The Electronic Frontier Foundation (EFF) argued that this is a violation of the protection from self-incrimination given by the Fifth Amendment. In 2012, the court ruled that under the All Writs Act, the defendant was required to produce an unencrypted hard drive for the court. 

In many jurisdictions, the legal status of forced disclosure remains unclear.

The 2016 FBI–Apple encryption dispute concerns the ability of courts in the United States to compel manufacturers' assistance in unlocking cell phones whose contents are cryptographically protected.

As a potential counter-measure to forced disclosure some cryptographic software supports plausible deniability, where the encrypted data is indistinguishable from unused random data (for example such as that of a drive which has been securely wiped).

A cryptosystem is a set of cryptographic algorithms that map ciphertexts and plaintexts to each other. 

Private-key cryptosystems

Private-key cryptosystems use the same key for encryption and decryption.

Caesar cipher

Substitution cipher

Enigma machine

Data Encryption Standard

Twofish

Serpent

Camellia

Salsa20

ChaCha20

Blowfish

CAST5

Kuznyechik

RC4

3DES

Skipjack

Safer

IDEA

Advanced Encryption Standard, also known as AES and Rijndael. 

Public-key cryptosystems

Public-key cryptosystems use a public key for encryption and a private key for decryption.

Diffie–Hellman key exchange

RSA encryption

Rabin cryptosystem

Schnorr signature

ElGamal encryption

Elliptic-curve cryptography

Lattice-based cryptography

McEliece cryptosystem

Multivariate cryptography

Isogeny-based cryptography

A white paper is a report or guide that informs readers concisely about a complex issue and presents the issuing body's philosophy on the matter. It is meant to help readers understand an issue, solve a problem, or make a decision. A white paper is the first document researchers should read to better understand a core concept or idea.

The term originated in the 1920s to mean a type of position paper or industry report published by some department of the UK government.

Since the 1990s, this type of document has proliferated in business. Today, a business-to-business (B2B) white paper is closer to a marketing presentation, a form of content meant to persuade customers and partners and promote a certain product or viewpoint. That makes B2B white papers a type of grey literature.

In government

The term white paper originated with the British government and many point to the Churchill White Paper of 1922 as the earliest well-known example under this name. In the British government, a white paper is usually the less extensive version of the so-called blue book, both terms being derived from the colour of the document's cover. 

White papers are a "tool of participatory democracy ... not [an] unalterable policy commitment". "White papers have tried to perform the dual role of presenting firm government policies while at the same time inviting opinions upon them." 

In Canada, a white paper is "a policy document, approved by Cabinet, tabled in the House of Commons and made available to the general public". The "provision of policy information through the use of white and green papers can help to create an awareness of policy issues among parliamentarians and the public and to encourage an exchange of information and analysis. They can also serve as educational techniques." 

White papers are a way the government can present policy preferences before it introduces legislation. Publishing a white paper tests public opinion on controversial policy issues and helps the government gauge its probable impact. 

By contrast, green papers, which are issued much more frequently, are more open-ended. Also known as consultation documents, green papers may merely propose a strategy to implement in the details of other legislation, or they may set out proposals on which the government wishes to obtain public views and opinion.

Examples of governmental white papers include, in Australia, Full Employment in Australia and, in the United Kingdom, the White Paper of 1939 and the 1966 Defence White Paper.

In Israeli history, the British White Paper of 1939 – marking a sharp turn against Zionism in British policy and at the time greeted with great anger by the Jewish Yishuv community in Mandatory Palestine – is remembered as "The White Paper" (in Hebrew Ha'Sefer Ha'Lavan ???? ???? – literally "The White Book").

In business-to-business marketing

Since the early 1990s, the terms "white paper" or "whitepaper" have been applied to documents used as marketing or sales tools in business. These white papers are long-form content designed to promote the products or services from a specific company. As a marketing tool, these papers use selected facts and logical arguments to build a case favorable to the company sponsoring the document.

B2B (business-to-business) white papers are often used to generate sales leads, establish thought leadership, make a business case, grow email lists, grow audiences, increase sales, or inform and persuade readers. The audiences for a B2B white paper can include prospective customers, channel partners, journalists, analysts, investors, or any other stakeholders.

White papers are considered to be a form of content marketing or inbound marketing; in other words, sponsored content available on the web with or without registration, intended to raise the visibility of the sponsor in search engine results and build web traffic. Many B2B white papers argue that one particular technology, product, ideology, or methodology is superior to all others for solving a specific business problem. They may also present research findings, list a set of questions or tips about a certain business issue, or highlight a particular product or service from a vendor. 

There are, essentially, three main types of commercial white papers:

Backgrounder: Describes the technical or business benefits of a certain vendor's offering; either a product, service, or methodology. This type of white paper is best used to supplement a product launch, argue a business case, or support a technical evaluation at the bottom of the sales funnel or the end of the customer journey. This is the least challenging type to produce, since much of the content is readily available in-house at the sponsor.

Numbered list: Presents a set of tips, questions, or points about a certain business issue. This type is best used to get attention with new or provocative views, or cast aspersions on competitors. Also called a listicle this is the fastest type to create; a numbered list can often be devised from a single brainstorming session, and each item can be presented as an isolated point, not part of any step-by-step logical argument.

Problem/solution: Recommends a new, improved solution to a nagging business problem. This type is best used to generate leads at the top of the sales funnel or the start of the customer journey, build mind share, or inform and persuade stakeholders, building trust and credibility in the subject. This is the most challenging type to produce, since it requires research gathered from third-party sources and used as proof points in building a logical argument.

While a numbered list may be combined with either other type, it is not workable to combine a backgrounder with a problem/solution white paper. While a backgrounder looks inward at the details of one particular product or service, a problem/solution looks outward at an industry-wide problem. This is rather like the difference between looking through a microscope and looking through a telescope.

Variants

"Blue paper" redirects here. For the urban legend, see Red Paper, Blue Paper. For other uses, see Blue pages, Blueprint, Blue book, and Construction paper.

Several variations on the colour theme exist:

The green paper is a proposal or consultative document rather than being authoritative or final.

The Red Book, the UK Chancellors Budget will set out the highlights and reasoning behind the governments proposed taxation and spending policies in a White Paper called The Financial Statement and Budget Report (FSBR) while an accompanying document called the Red Book will contain the detailed financial costings of the policies, estimates of revenue and forecasts for public sector borrowing. 

Two others are much less well established:

A blue paper sets out technical specifications of a technology or item of equipment. 

A yellow paper is a document containing research that has not yet been formally accepted or published in an academic journal. It is synonymous with the more widely used term preprint.

Ledger is the first peer-reviewed academic journal dedicated to cryptocurrency and blockchain technology research. The journal covers topics that relate to cryptocurrencies such as bitcoin. This includes aspects of mathematics, computer science, engineering, law, economics and philosophy. The focus according to Wilmer is "blockchain technology research." It is funded by Coin Center, a nonprofit. 

The journal is open access. It is published by the University Library System of the University of Pittsburgh and is cosponsored by the University of Pittsburgh Press. 

Creation

The idea for the journal was born out of a discussion between managing editors Peter R. Rizun and Christopher E. Wilmer, on the bitcoin forum bitcointalk.org.

Wilmer envisioned ledger as a journal for "people passionate about the technology, to publish their research." Wilmer called into question the reliability of 'white papers' that became common in the cryptocurrency boom. According to Wilmer, the Ledger Journal receives two to four submissions a week, and many are of poor quality. “Occasionally we get submissions with no citations." Wilmer's vision for Ledger was to use a more a traditional peer review system. 

A call for papers was issued on 15 September 2015 with the deadline set to 31 December 2015. However, this was delayed while formalising the review process. The inaugural issue was not published until December 2016. 

Related persons and organizations

Rizun is a physicist and entrepreneur, who lives in Vancouver, Canada. 

Wilmer is an assistant professor in the Swanson School of Engineering’s Chemical & Petroleum Engineering Department. He is the author of Bitcoin for befuddled. Wilmer first used bitcoin to purchase honey caramels from a beekeeper. 

The University of Pittsburgh was featured in the documentary The Rise and Rise of Bitcoin. 

Decentralized finance (often stylized as DeFi) offers financial instruments without relying on intermediaries such as brokerages, exchanges, or banks by using smart contracts on a blockchain. DeFi platforms allow people to lend or borrow funds from others, speculate on price movements on assets using derivatives, trade cryptocurrencies, insure against risks, and earn interest in savings-like accounts. DeFi uses a layered architecture and highly composable building blocks. Some applications promote high interest rates but are subject to high risk. Coding errors and hacks have been common in DeFi. 

Decentralized exchanges (abbreviated DEXs) are alternative payment ecosystems with new protocols for financial transactions that emerged within the framework of decentralized finance, which is part of blockchain technology and fintech. 

CEXs (centralized exchanges), DEXs and DEX aggregators are all built on the multi-layered DeFi architecture or components, where each layer serves a well-defined purpose. (See Figure: Multi-layered Architecture of the DeFi Stack).

While they share common components of the first four layers, such as Settlement layer, Asset layer, Protocol layer and Application layer, DEX aggregators have an additional component or Aggregator layer, which allows them to connect and interact with other DEXs via smart contracts. 

The Ethereum blockchain popularized smart contracts, which are the basis of DeFi, in 2017. Other blockchains have since implemented smart contracts.

MakerDAO is a prominent lending DeFi platform based on a stablecoin that was established in 2017. It allows users to borrow DAI, a token pegged to the US dollar. Through a set of smart contracts that govern the loan, repayment, and liquidation processes, MakerDAO aims to maintain the stable value of DAI in a decentralized and autonomous manner. 

In June 2020, Compound Finance, a decentralized finance protocol enabling users to lend or borrow cryptocurrency assets and which provides typical interest payments to lenders, started rewarding lenders and borrowers with a cryptocurrency called Comp. This token, which is used for running Compound, can also be traded on cryptocurrency exchanges. Other platforms followed suit, leading to stacked investment opportunities known as "yield farming" or "liquidity mining", where speculators shift cryptocurrency assets between pools in a platform and between platforms to maximize their total yield, which includes not only interest and fees but also the value of additional tokens received as rewards. 

In July 2020, The Washington Post described decentralized finance techniques and the risks involved. In September 2020, Bloomberg said that DeFi made up two-thirds of the cryptocurrency market in terms of price changes and that DeFi collateral levels had reached $9 billion. Ethereum saw a rise in developers during 2020 due to the increased interest in DeFi. 

DeFi has attracted venture capitalists such as Andreessen Horowitz and Michael Novogratz. 

The Economist regarded the future of digital finance in 2022 as a "three-way fight" between: Big Tech, such as Facebook with its digital wallet; "big rich countries" that have been testing their own digital currencies; and software developers "building all sorts of applications" to decentralize finance. Handling the risks presented by crypto-assets already valued at $2.5 trillion was a particular challenge for US regulators. 

Key characteristics

DeFi revolves around decentralized applications, also known as DApps, that perform financial functions on distributed ledgers called blockchains, a technology that was made popular by Bitcoin and has since been adapted more broadly. Rather than transactions being made through a centralized intermediary such as a cryptocurrency exchange or a traditional securities exchange, transactions are directly made between participants, mediated by smart contract programs. These smart contracts, or DeFi protocols, typically run using open-source software that is built and maintained by a community of developers. 

DApps are typically accessed through a browser extension or application. For example, MetaMask allows users to directly interact with Ethereum through a digital wallet. Many of these DApps can be linked to create complex financial services. For example, stablecoin holders can lend assets like USD Coin or DAI to a liquidity pool in a borrow/lending protocol like Aave, and allow others to borrow those digital assets by depositing their own collateral. The protocol automatically adjusts interest rates based on the demand for the asset. Some DApps source external (off-chain) data, such as the price of an asset, through blockchain oracles. 

Additionally, Aave introduced "flash loans", which are uncollateralized loans of an arbitrary amount that are taken out and paid back within a single blockchain transaction. Many exploits of DeFi platforms have used flash loans to manipulate cryptocurrency spot prices. 

Another DeFi protocol is Uniswap, which is a decentralized exchange (DEX) set up to trade tokens issued on Ethereum. Rather than using a centralized exchange to fill orders, Uniswap pays users to form liquidity pools in exchange for a percentage of the fees collected from traders swapping tokens in and out of the liquidity pools. Because no centralized party runs Uniswap (the platform is governed by its users), and any development team can use the open-source software, there is no entity to check the identities of the people using the platform and meet KYC/AML regulations. As of 2020, it is not clear what position regulators will take on the legality of such platforms. 

Decentralized exchanges

Decentralized exchanges (DEX) are a type of cryptocurrency exchange which allows for direct peer-to-peer cryptocurrency transactions to take place without the need for an intermediary, so they are fundamentally differerent from centralized exchanges (CEX). 

In transactions made through decentralized exchanges, the typical third party entities which would normally oversee the security and transfer of assets (e.g. banks, stockbrokers, online payment gateways, government institutions, etc.) are substituted by a blockchain or distributed ledger. Some common methods of operation include the use of smart contracts or order book relaying, although many other variations are possible and with differing degrees of decentralization. 

Because traders on a decentralized exchange often do not need to transfer their assets to the exchange before executing a trade, decentralized exchanges reduce the risk of theft from hacking of exchanges, but liquidity providers do need to transfer tokens to the decentralized exchange. Decentralized exchanges are also more anonymous than exchanges that implement know your customer (KYC) requirements.

There are some signs that decentralized exchanges have been suffering from low trading volumes and market liquidity. The 0x project, a protocol for building decentralized exchanges with interchangeable liquidity attempts to solve this issue. 

Disadvantages

Due to a lack of KYC processes, and no way to revert a transaction, users are at a loss if they are ever hacked for their passwords or private keys. Additionally, users staking in DeFi protocols can suffer what is called an impermanent loss.

Although liquidity pool DEX are the most widely used, they may have some drawbacks. The most common problems of liquidity pool DEXes are market price impact, slippage, and front running.

Price impact occurs because of the AMM (Automated Market Makers) nature itself — the larger the deal, the stronger impact it has on the price. For example, if the constant product AMM is in use, every deal must keep the product xy = k constant, where x and y are quantities of two cryptocurrencies (or tokens) in the pool. Price impact is non-linear, so the larger is the input amount ?x, the lower is the final ratio y / x that gives an exchange price. The problem is mostly significant for relatively large deals versus the liquidity pool size. 

Front running is a special type of attack in public blockchains when some participant (usually a miner) seeing an upcoming trading transaction puts his own transaction ahead (playing with a transaction fee for example), making the initial transaction less profitable or even reverted. To provide some protection against front running attacks, many DeFi exchanges offer a slippage tolerance option for end-users. This option serves as a safeguard, allowing users to set a limit on the worst acceptable price they are willing to accept from the time of transaction signing.

Degrees of decentralization

A decentralized exchange can still have centralized components, whereby some control of the exchange is still in the hands of a central authority. The governance of a DeFi platform, typically as part of a Decentralized Autonomous Organization, is done through tokens that grant voting rights and are distributed amongst participants. However, the majority of these tokens are often held by few individuals and are rarely used to vote. 

In July 2018, the decentralized exchange Bancor was reportedly hacked and suffered a loss of $13.5M in assets before freezing funds. In a Tweet, Charlie Lee, the creator of Litecoin spoke out and claimed an exchange cannot be decentralized if it can lose or freeze customer funds. 

Operators of decentralized exchanges can face legal consequences from government regulators. One example is the founder of EtherDelta, who in November 2018 settled charges with the U.S. Securities and Exchange Commission over operating an unregistered securities exchange. 

Errors and hacking

Coding errors and hacks are common in DeFi. Blockchain transactions are irreversible, which means that an incorrect or fraudulent DeFi transaction cannot be corrected easily.

The person or entity behind a DeFi protocol may be unknown, and may disappear with investors' money. Investor Michael Novogratz has described some DeFi protocols as "Ponzi-like". 

DeFi has been compared to the initial coin offering craze of 2017, part of a cryptocurrency bubble. Inexperienced investors are at particular risk of losing money because of the sophistication required to interact with DeFi platforms and the lack of any intermediary with customer support. On the other hand, as the code for DeFi smart contracts is generally open-source software that can be copied to set up competing platforms, experienced users and user-created bots might create instabilities as funds shift between platforms which share the same code. In addition, DeFi platforms might inadvertently provide incentives for cryptocurrency miners to destabilize the system. 

In 2021, half of cryptocurrency crime was related to DeFi. This rise has been attributed to a combination of developer incompetence and non-existent or poorly enforced regulations. Theft from DeFi can come from either external hackers stealing from vulnerable projects, or "rug pulls", where the developers and influencers promote a project and then take the money, as a form of pump-and-dump. 

Regulation

In October 2021, the FATF included DeFi in the guidance for crypto service providers, making the authority's aim to regulate this type of asset. They are expecting each individual country to determine if individuals involved in DeFi can be considered a virtual asset provider and be subjected to the FATF's guidelines. 

A decentralized autonomous organization (DAO), sometimes called a decentralized autonomous corporation (DAC),[a] is an organization managed in whole or in part by decentralized computer program, with voting and finances handled through a blockchain. In general terms, DAOs are member-owned communities without centralized leadership. The precise legal status of this type of business organization is unclear. 

A well-known example, intended for venture capital funding, was The DAO, which amassed 3.6 million ether (ETH)—Ethereum's mining reward—then worth more than US$70 million in May 2016, and was hacked and drained of US$50 million in cryptocurrency weeks later. The hack was reversed in the following weeks, and the money restored, via a hard fork of the Ethereum blockchain. Most Ethereum miners and clients switched to the new fork while the original chain became Ethereum Classic.

The governance of DAOs is subject to controversy. As these typically allocate and distribute tokens that grant voting rights, their accumulation may lead to concentration of power. 

Background

Although the term may be traced back to the 1990s, it was not until 2013 that it became more widely adopted. Although some argue that Bitcoin was the first DAO, the term is only understood today as organizations deployed as smart contracts on top of an existing blockchain network. 

Decentralized autonomous organizations are typified by the use of blockchain technology to provide a secure digital ledger to track digital interactions across the internet, hardened against forgery by trusted timestamping and dissemination of a distributed database. This approach eliminates the need to involve a mutually acceptable trusted third party in any decentralized digital interaction or cryptocurrency transaction. The costs of a blockchain-enabled transaction and of the associated data reporting may be substantially offset by the elimination of both the trusted third party and of the need for repetitive recording of contract exchanges in different records. For example, the blockchain data could, in principle and if regulatory structures permit it, replace public documents such as deeds and titles. :?42? In theory, a blockchain approach allows multiple cloud computing users to enter a loosely coupled peer-to-peer smart contract collaboration. :?42? 

Vitalik Buterin proposed that after a DAO is launched, it might be organized to run without human managerial interactivity, provided the smart contracts are supported by a Turing-complete platform. Ethereum, built on a blockchain and launched in 2015, has been described as meeting that Turing threshold, thus enabling such DAOs. Decentralized autonomous organizations aim to be open platforms through which individuals control their identities and their personal data. 

Governance

DAO governance is coordinated using tokens or NFTs that grant voting powers. Admission to a DAO is limited to people who have a confirmed ownership of these governance tokens in a cryptocurrency wallet, and membership may be exchanged. Governance is conducted through a series of proposals that members vote on through the blockchain, and the possession of more governance tokens often translates to greater voting power. Contributions from members towards the organizational goals of a DAO can sometimes be tracked and internally compensated. Inactive holders of governance tokens can be a major obstacle for DAO governance, which has led to implementations allowing voting power to be delegated to other parties.

Issues

Social

Tokens that grant voting powers are often not used to vote. Inactive or non-voting shareholders in DAOs often disrupt the organization's possible functionality. 

Another risk is the concentration of power in the case that individuals accumulate large amounts of tokens that grant voting power. Concentration of these tokens defeats the ambitions to distribute governance power. In a study of Decentralised Finance DAOs, the distribution of tokens was shown to be highly concentrated among a small population of holders. 

Legal status, liability, and regulation

The precise legal status of this type of business organization is generally unclear, and may vary by jurisdiction. On July 1, 2021, Wyoming became the first US state to recognize DAOs as a legal entity. American CryptoFed DAO became the first business entity so recognized. Some previous approaches to blockchain based companies have been regarded by the U.S. Securities and Exchange Commission as illegal offers of unregistered securities. Although often of uncertain legal standing, a DAO may functionally be a corporation without legal status as a corporation: a general partnership. Known participants, or those at the interface between a DAO and regulated financial systems, may be targets of regulatory enforcement or civil actions if they are out of compliance with the law. 

In June 2022, the venture capital firm Andreessen Horowitz published an "Entity selection framework" describing organizational alternatives for DAOs with substantial presence in the United States. 

Security

A DAO's code is difficult to alter once the system is up and running, including bug fixes that would be otherwise trivial in centralized code. Corrections to a DAO require writing new code and agreement to migrate all the funds. Although the code is visible to all, it is hard to repair, thus leaving known security holes open to exploitation unless a moratorium is called to enable bug fixing. 

In 2016, a specific DAO, "The DAO", set a record for the largest crowdfunding campaign to date. Researchers pointed out multiple problems with The DAO's code. The DAO's operational procedure allowed investors to withdraw at will any money that had not yet been committed to a project; the funds could thus deplete quickly. Although safeguards aimed to prevent gaming shareholders' votes to win investments, there were a "number of security vulnerabilities". These enabled an attempted large withdrawal of funds from The DAO to be initiated in mid-June 2016. On July 20, 2016, the Ethereum blockchain was forked to bail out the original contract.

DAOs can be subject to coups or hostile takeovers that upend its voting structures especially if the voting power is based upon the number of tokens one owns. An example of this occurred in 2022, when one individual collected enough tokens to give themselves voting control over Build Finance DAO, which they then used to drain the DAO of all its money. 

List of notable DAOs

This is a dynamic list and may never be able to satisfy particular standards for completeness. You can help by adding missing items with reliable sources.

Name Token Use cases Network Launch Status

The DAO DAO Venture capital Ethereum April 2016 Defunct late 2016 due to hack 

ConstitutionDAO PEOPLE Purchasing an original copy of the Constitution of the United States Ethereum November 2021 Defunct 

PleasrDAO PEEPS A group of art collectors who own the sole copy of the Wu Tang Clan album Once Upon a Time in Shaolin Ethereum April 2021 Operational

FreeRossDAO FREE Clemency for Ross Ulbricht, criminal justice reform advocacy organization Ethereum December 2021 Operational

AssangeDAO JUSTICE Purchased Clock, an NFT artwork by Pak, to fund legal defense of WikiLeaks' founder Julian Assange Ethereum February 2022 Operational

MakerDAO MKR Dai (cryptocurrency) stablecoin maintainer and regulator, lender Ethereum December 2017 Operational

Uniswap UNI Decentralized exchange (DEX), Automated Market Making (AMM) Ethereum & Celo November 2018 Operational 

Overview of highest-funded crowdfunding projects

Rank Project Category Platform End date Target Amount

raised Notes

1 EOS Blockchain Ethereum June 1, 2018 — $4,100,000,000

(7.12 million ETH) EOS is a blockchain operating system designed to support commercial decentralized applications. The amount in US dollars is based on an exchange rate of $576 per ether.

2 Star Citizen Video game Kickstarter, Independent Ongoing $2M $569,640,446+ Space combat video game being developed by Chris Roberts, designer of Wing Commander. By April 19, 2013, a combined US$9,061,882 had been raised on Kickstarter and Roberts' own website. It was listed as a Guinness World Record in 2014, after having raised more than US$40,680,576 through Roberts' own website. By June 13, 2020, Star Citizen had raised a total of US$300 million, spurred by special events Invictus Launch Week and Alien Week. Most of this total comes from pledges sold on Roberts' website and rewarded with in-game items. 

3 Filecoin Blockchain Ethereum September 7, 2017 — $257,000,000

Filecoin is a decentralized data storage application.

4 Tezos Blockchain Independent July 14, 2017 — $232,000,000 Tezos is a self-governing blockchain.

5 U-Haul Investors Club Business equipment Independent Ongoing (started in 2011) — $205,358,000 (updated weekly after COB on Tuesdays) Operated by AMERCO (the parent company of U-Haul) this crowdfunding platform allows investors to invest in U-Haul assets such as trucks, trailers, occasionally in real estate, and even items such as furniture pads and equipment dollies. Investors purchase "U-Notes" which are available in $100 increments (and require a $100 minimum investment, subsequent additions to the account require a $25 minimum) and have maturities from 2-30 years (depending on what is offered). Investors can invest via individual, business or trust accounts, Coverdell Education Savings accounts, and both traditional and Roth IRA's. Payments are made quarterly in arrears, of which (similar to a mortgage amortization) part of the payment is interest and the rest a partial return of principal. The platform is limited to United States investors only, interest is not earned on amounts not invested in U-Notes, and there is virtually no secondary trading market (notes can only be traded between club investors) making them highly illiquid; as such, investors are advised that they will likely need to hold their investments to maturity. Investors may also earn credits for referring other investors.

6 The DAO Blockchain Ethereum May 28, 2016 $500K $160,000,000 (in ETH) A publicly created and crowdfunded Decentralized Autonomous Organization, built on the Ethereum blockchain, that stored and transmitted Ether and Ethereum-based assets.

Funds were held programatically by design in the cryptocurrency known as Ether, the actual USD amount raised varied in line with the Ether|USD exchange rate at any given moment. Final raised amount was ETH 11.5 million. The amount listed is the conversion value of the raised Ethereum at the campaign end date.

7 Sirin Labs (SRN) Mobile Ethereum, Bitcoin December, 2017 — $158,000,000 A blockchain phone that makes it easier to use digital currency. Expected to sell for over $1000 with 25,000 units pre-ordered. 

8 Bancor Blockchain Ethereum June 12, 2017 $100M $153,000,000 (in ETH) The Bancor protocol is a smart contracts platform built on top of the Ethereum blockchain.

9 Polkadot Blockchain Ethereum October 27, 2017 - $144,300,000 Polkadot is a heterogeneous multichain which posits a trustless fully decentralised "federation" of public and private blockchains with trust-free access to each other.

10 Status Blockchain Ethereum June 21, 2017 $12M $103,000,000

11 TenX Blockchain Ethereum June 24, 2017 $80M $80,000,000

(245,832 ETH) TenX offer a debit card system to customers and combine that with an open-source backend that allows TenX to connect any blockchain through hashed timelock contracts (HTLCs). TenX raised 100,000 ETH in a pre-sale and another 145,000 ETH equivalent during their token sale on June 24, 2017.

12 BANKEX Blockchain Ethereum December 26, 2017 $50M $70,600,000

BANKEX is a blockchain-based distributed financial technology platform. It allows people and enterprises to create and trade their digital assets represented as smart asset tokens on a blockchain. 

13 TRON Blockchain Ethereum Sep 2, 2017 $70M $70,000,000

TRON is a blockchain project that supports the global digital entertainment system. As an open-source project, it supports various types of smart contracts and contract systems such as Bitcoin, Ethereum and EOS.

14 ?ternity Blockchain Ethereum Jun 9, 2017 — $62,500,000.00 ?ternity is a new type of open-source, public, Blockchain-based distributed computing platform that innovates and expands upon existing platforms such as Bitcoin, Ethereum. Real-world data can interface with smart contracts through decentralized oracles. True scalability and trust-less Turing-complete state channels sets ?ternity apart from all other Blockchain 2.0 projects. Contribution was divided into two phases and closed by 9 June 2017. Total amount raised in Phase 1 + Phase 2 is over $62.5 million (at ETH and BTC valuation on 9 June 2017).

15 Sono Motors Sion Solar electric vehicle Independent Jan 20, 2020 50M € $59,226,997

(€53.342.998 ) Sono Motors is a Munich based company that develops an electric vehicle that can be charged by solar cells that are integrated in the vehicles outer skin. The system is also prepared for vehicle to grid/vehicle applications as well as car and ride sharing.

16 MobileGo Blockchain Ethereum, Waves platform May 24, 2017 — $53,069,235

MobileGo tokens will be used to gamify the mobile platform, and to incentivize gamers for loyalty and participation through rewards. MobileGo tokens will also allow for smart contract technology. MobileGo tokens will allow for the development of a decentralized virtual mobile gamer marketplace, the ability for gamer vs. gamer decentralized match play, and decentralized tournaments run on smart contracts.

17 The David Movie Movie Independent Mar 31, 2023 $60,982,236 $50,814,941 An animated movie based on the Biblical character David. Produced by Sunrise and being published by Angel Studios.

18 Surprise! Four Secret Novels by Brandon Sanderson Publishing Kickstarter Backerkit Mar 31, 2022 $1M $45,574,127 A subscription-based publishing of four "secret" novels by author Brandon Sanderson (i.e., novels which Sanderson wrote without telling anyone that they were in progress). Exceeded Dragonsteel Entertainment's previous Kickstarter in 6 hours. Fastest Kickstarter to hit $4M at the time. Reached $10M in under 10 hours, $20M in under 60 hours, $40M within hours of ending. Most funded Kickstarter ever.

19 Basic Attention Token Blockchain Ethereum May 31, 2017 — $35,000,000

Basic Attention Token is a token on the Brave Browser. BAT allows marketers to sell and publishers to buy ads without exposing users to constant tracking. Targeting is handled by the browser. The user gets paid a small amount for viewing ads. The initial coin offering sold out in under 30 seconds. 

20 Polybius Bank Blockchain bank Bitcoin, Ethereum July 5, 2017 $25M for bank with Digital Pass.

(Ladderized target with flexible plan.) $31,645,088

(?12,379.689)

= 3,650,521 PLBT Project: Polybius Bank is a project aimed to create the world's first fully digital bank that is EU-regulated and crowdfunded by its own users through tokens ($PLBT).

21 CyberMiles Blockchain, E-commerce Ethereum, Independent November 22, 2017 $30M $30,000,000

(71,850 ETH) CyberMiles is an in-development blockchain protocol specifically designed and optimized for e-commerce.

22 Solve.Care Blockchain, Healthcare Ethereum Apr 30, 2018

$30m 30,000,000 Solve.Care is for coordination, administration and payments in the healthcare industry. Patients will be able to make reservations and share relevant data.

23 The Chosen TV series Angel Studios Ongoing $13M (Season 1)

$10M (Season 2)

$28,700,000 TV series based on the life of Jesus Christ. The value comprises $10,200,000 for Season 1 and $6,544,120 for Season 2 as of 21 July 2020 

24 Glowforge Manufacturing hardware WordPress, Elevato Oct 24, 2015 $100,000 $27,907,995 Glowforge uses a beam of light the width of a human hair to cut, engrave, and shape designs from a variety of materials. Called a "3D laser printer" by the makers, in actuality it is a laser cutter.

25 BitClave Blockchain Ethereum November 29, 2017 — $25,547,000 BitClave is using blockchain to eliminate ad service “middlemen” and create a direct connection between businesses and customers.

26 We Build The Wall Community GoFundMe — $1.0B $25,425,600 Construction of the Border barrier at the Mexico–United States border. The idea originated and gained popularity from the political platform of the Donald Trump 2016 presidential campaign. The project raised over $9 million in only 3 days after its launch.

27 Aragon Blockchain Ethereum May 17, 2017 — $25,000,000 Aragon is a management platform for decentralized organizations. Aragon implements organizational features such as governance, fundraising, payroll and accounting. Aragon launched a token sale for the Aragon Network, the world's first decentralized jurisdiction. The Aragon Network will provide organizations subscribed to it with services such as a decentralized arbitration system or a code upgradeability mechanism. The token sale closed in about 15 minutes, peaking at a rate of $122,000 per second.

28 Pebble Time Smartwatch Kickstarter Mar 27, 2015 $500K $20,338,986 The Pebble Time is the second generation version of the smartwatch called the Pebble. The Pebble itself was one of the highest backed projects on Kickstarter.

29 Prison Architect Video game Independent, Steam Early Access Oct 6, 2015 — $19,000,000 Prison construction and management simulation game by Introversion Software. It was made available as a paid alpha pre-order on September 25, 2012 and was one of the initial games in Valve's Steam Early Access program when it was launched.

30 Ethereum Blockchain Independent Sep 2, 2014 — $18,300,000 Ethereum is a public blockchain-based distributed computing platform, featuring smart contract functionality and a cryptocurrency, Ether.

31 Time for the Planet Climate change Independent Ongoing 1B € $17,020,394

(€15.853.128 ) Time for the Planet is a citizens' movement fighting against global warming. This movement invests in innovations to reduce GHG emissions on a global scale. To have a better chance of being deployed, a successful entrepreneur will be recruited to find the best business plan for this innovation, and money will be invested on this project. Finally, all innovations will be shared in a free license to allow everyone to copy them.

32 Power Ledger Blockchain Ethereum October 6, 2017 — $17,000,000

= 34,000,000 AUD POWR token sale is Australia's first initial coin offering. The company raised half of the total funds in three days during its pre-sale.

33 Sandclock Blockchain Ethereum October 26, 2021 — $16,900,000 Quartz is the governance token of the Sandclock ecosystem. Sandclock is a fintech built on the blockchain and offers users the ability to save, invest, donate and spend. 

34 Cosmos Blockchain Bitcoin, Ethereum Apr 6, 2017 $10m $16,800,000

Cosmos aims to create a network of ledgers to solve long-standing problems in the cryptocurrency and blockchain communities. One of the most prominent use cases is decentralized exchanging from one currency to another. Currently this is largely done on centralized exchanges

35 TokenCard Blockchain Ethereum May 3, 2017 — $16,516,286

TokenCard is a depositless Ethereum-based mobile banking platform that aims to integrate the Ethereum Economy into the daily life of consumers globally.

36 Waves platform Blockchain Independent May 31, 2016 — $16,436,095

Waves (stylised WAVES) is a non-permissioned, non-privatized blockchain that intends to deal with banks national currencies. It raised 2 million in 24 hours and has a partnership with the Mycelium wallet. It raised 29,636 bitcoins.

37 Qtum Blockchain hybrid blockchain platform March 21, 2017. — $15,664,829.30 Qtum [pronounced Quantum] is a hybrid blockchain platform that runs the EVM on bitcoins core allowing smart contracts to exist in a mobile environment.

38 Cofound.it Blockchain Ethereum June 7, 2017 56565 ETH ($~14.8M) $14,700,000 A distributed VC ecosystem. Cofound.it is a distributed global platform that connects exceptional startups, experts and investors worldwide. It will first be built by the blockchain community for the blockchain community — and then for the whole world.

39 Coolest Cooler Computing hardware Kickstarter Aug 29, 2014 $50K $13,285,226 Portable 60 quart cooler designed by Ryan Grepper that contains a battery powered rechargeable blender, waterproof Bluetooth speaker, USB charger, cutting board, plates, among other features. 

40 Flow Hive Food Indiegogo Apr 19, 2015 $70K $13,289,097 Flow Hive is a new type of domesticated bee hive box with a valve, where the beekeeper can extract honey from the hive without disturbing the bees.

41 Frosthaven Board game Kickstarter May 1, 2020 $500K $12,969,608 Fantasy cooperative board game and the sequel to Gloomhaven.

42 Ubuntu Edge Computing hardware Indiegogo Aug 21, 2013 $32M $12,814,196 The Ubuntu Edge was a proposed "high concept" smartphone announced by Canonical Ltd. on 22 July 2013.

43 Shroud of the Avatar: Forsaken Virtues Video game Kickstarter, Independent, Steam Early Access Ongoing $1M $12,658,636 Richard Garriott returns to the fantasy RPG genre. Of the total amount, $1,919,275 was raised on Kickstarter.

44 Kingdom Death: Monster 1.5 Board game Kickstarter January 7, 2017 — $12,393,139 A massive cooperative board game about survival in a nightmare-horror world. Original Kickstarter campaign that raised $2,049,721 was surpassed in 2 hours. 

45 Critical Role: The Legend of Vox Machina Animated Special Animated series Kickstarter April 19, 2019 $750K $11,385,449 Animated special based on the web series Critical Role which was funded in one hour and then was expanded to a ten episodes animated series after reaching stretch goals. When the campaign closed, it was one of the most quickly funded in Kickstarter history, and was the most funded Kickstarter for TV and film projects. In November 2019, Amazon Prime Video announced that they had acquired the streaming rights to The Legend of Vox Machina, and had commissioned 14 additional episodes (two additional episodes for season 1 and a second season of 12 episodes). 

46 ICONOMI Digital Assets Management platform Other Ethereum Sep 29, 2016 2000 BTC ($~1.2M) $10,682,516.42 ICONOMI Digital Assets Management platform enables simple access to a variety of digital assets and combined Digital Asset Arrays.

47 BauBax Other Kickstarter, Indiegogo September 2015 $20K $10,271,965

The campaign was launched on July 7, 2015. By August 2015, BauBax had raised $3.7 million and was the most funded clothing project in Kickstarter history. By September 11, 2015, it had raised $9.7 million. The Travel Jacket comes with 15 unique features including a built-in Neck Pillow, Eye Mask, Gloves, Earphone Holders, Drink Pocket and Tech Pockets of all sizes. Available in four styles: hoodie/sweatshirt, fleece lined bomber, wrinkle free blazer with removable hoodie, and a windbreaker.

48 Pebble Smartwatch Kickstarter May 18, 2012 $100K $10,266,845 E-Paper smartwatch. Third highest funded project on Kickstarter.Shipping to backers began on 23 Jan 2013.

49 Avatar Legends: The Roleplaying Game Tabletop role-playing game Kickstarter Sep 3, 2021 $50K $9,535,317 A tabletop role-playing game developed by Magpie Games, based on the animated series Avatar: The Last Airbender and The Legend of Korra. The game is built on the Powered by the Apocalypse framework.

50 Modular Gaming Table Furniture Kickstarter Oct 10, 2020 $1M $8,808,136 A customizable table designed for tabletop and role-playing gamers designed by Taunton, Massachusetts-based woodworking company and gaming accessory manufacturer Wyrmwood Gaming. The table is a convertible platform allowing it to be used as either a coffee table or a dining table with removable toppers and magnetic rails along the edge that can hold different table accessories meant for gaming. The project hit its target goal of $1,000,000 in just ten minutes and raised $4,000,000 in its first day. It was the second-most funded tabletop gaming project on Kickstarter for the year 2020. As of February 21, 2021, it is the tenth most-successfully funded project on Kickstarter.

51 Exploding Kittens Board game Kickstarter Feb 19, 2015 $10K $8,782,571 Card game featuring exploding kittens, designed by Elan Lee, Matthew Inman, and Shane Small. The project hit its primary goal in only 8 minutes, exceeded $100,000 (10x its goal) in less than one hour, $1,000,000 (100x its goal) in less than 8 hours, and $2,000,000 (200x its goal) in just over 24 hours. By January 28, 2015, it passed 107,000 backers, making it the most backed Kickstarter to date. 

52 Golem Blockchain Ethereum, Independent Nov 11, 2016 $8.6M $8,600,000

Distributed, open sourced, supercomputer built on the Ethereum network. Made up of a global sharing economy network of computers that 'rent' out their computing power. Project hit its goal in 29 minutes.

53 Ouya Video game Kickstarter Aug 9, 2012 $950K $8,596,474 Android-based video game console. Industrial design by Yves B?har. Highest funded video game project entirely funded on Kickstarter. Development units began shipping in March 2013. Officially released in June 2013.

54 Gut Wei?enhaus Other Companisto Mar 27, 2015 $2M $8,148,450 Real estate

55 Snapmaker 2.0: Modular 3-in-1 3D Printers 3D printing Kickstarter Jun 6, 2019 $10K $7,850,866 Snapmaker 2.0 is a modular 3-in-1 3D printer, which has 3D printing, laser engraving, cutting, and CNC carving function. The project reached its funding goal in less than 1 minute. It also became the fastest ever project to raise $1m on Kickstarter, at just 7 minutes. It eventually raised over 7.8M USD, making it the most funded Technology project in Kickstarter history.

56 Shenmue III Video game Kickstarter, Independent Sep 1, 2018 $2M $7,063,329 $6,333,295 was raised on Kickstarter, making Shenmue III the highest-funded video game project in Kickstarter history.

57 The Wingfeather Saga TV series Angel Studios, Kickstarter Ongoing $10.1M $6,979,041 TV series based on the children's book series of the same name. The value comprises $265,880 of $110,000 goal for a pilot episode , $4,997,000 of $5,000,000 max for Season 1 and $1,715,738 of $5,000,000 max for Season 2 .

58 The Way of Kings, Leatherbound Edition Publishing Kickstarter Aug 7, 2020 $250,000 $6,788,517 The response to this was significantly higher than Dragonsteel Entertainment anticipated. The "stretch goals" had to be adjusted multiple times, and then more were added after everything was reached in the first 6 hours. It was fully funded in 3 minutes, and reached over a million dollars within 10. At the time the campaign ended, it was the most funded Kickstarter campaign in the Publishing category, and the 14th over all of Kickstarter history.

59 Mystery Science Theater 3000 Series Kickstarter May 7, 2021 $5.5M $6,518,912 Raised to fund season 13 of Mystery Science Theater 3000 and the creation of the Gizmoplex, an online platform to show these new episodes as well as to show reruns of past episodes and host live events.

60 FirstBlood Crowdsale Software Ethereum Sep 26, 2016 $5,500,000 $6,267,767.32 FirstBlood is the first decentralized app, built on top of Ethereum, that allows eSports enthusiasts to compete in their favorite games through a decentralized, automated platform. The FirstBlood Token ("1S?"), sold during its crowdsale, is a utility token that can be used on FirstBlood's decentralized software.

The campaign raised over $5 million in less than five minutes. 

61 Pono Music Computing hardware Kickstarter Apr 15, 2014 $800K $6,225,354 Digital music player using the FLAC audio file format under development by musician Neil Young and his company Pono Music.

62 Mayday PAC Other Independent Jul 4, 2014 $6M $6,132,554

Super PAC founded by Lawrence Lessig with the purpose of pushing for a United States Congress dedicated to reforming campaign finance laws by 2016. The crowdfunding round took place in two cycles. The first $1M goal was started on May 1, and was reached on May 13, and the second, $5M goal was started on June 4 and was reached on July 4, at 9:30 pm EST - 9 hours short of the deadline of 6 am, July 5, EST (or midnight in Hawaii.) After the crowdfunding deadline, Mayday PAC raised an additional $4M from large donors.

As of May 22, 2016, Mayday PAC is the largest crowdfunding campaign for non-profit purposes.

63 Lucyd Blockchain, Wearable technology Ethereum Feb 28, 2019 $6m $6,100,000 Community-driven augmented reality project. Has since launched an eshop for advanced eyewear. Developing blockchain apps for augmented reality.

64 Fidget Cube Other Kickstarter Oct 19, 2016 $15K $6,038,945 A desk toy designed to help users focus. 

65 Mystery Science Theater 3000 Series Kickstarter Dec 11, 2015 $2M $5,764,229 $5,764,229 from 48,270 backers, with an additional $600,000 in backer add-ons to film season 11 of Mystery Science Theater 3000

66 Veronica Mars Movie Kickstarter Apr 13, 2013 $2M $5,702,153 Feature-length film continuation of the Veronica Mars television series.

67 Lisk Software Bitcoin, Independent Mar 21, 2016 — $5,700,000

Lisk is a crypto-currency and decentralized application platform. As a crypto-currency it provides a decentralized payment system and digital money network. The Lisk decentralized application platform allows the deployment, distribution and monetisation of decentralized applications and custom blockchains (sidechains) onto the Lisk blockchain.

68 Bloodstained: Ritual of the Night Video game Kickstarter Jun 12, 2015 $500,000 $5,545,991 Metroidvania video game, by former Castlevania producer Koji Igarashi. Succeeded Torment: Tides of Numenera as the highest funded Kickstarter video game, was succeeded by Shenmue III in July 2015. 

69 DigixDAO Crowdsale

Blockchain Ethereum Mar 30, 2016 $500K $5,500,000 DigixDAO crowdsale offered DGD tokens. The sale concluded in a mere 12 hours as the maximum was reached.

70 The Grid Software Independent Ongoing $70K $5,489,376

Website builder that uses Artificial intelligence algorithms to design and build websites based on content. 

71 Project Bring Back Reading Rainbow for Every Child, Everywhere Movie Kickstarter Jul 2, 2014 $1M $5,408,916 Make the iPad version of Reading Rainbow available on the web, other mobile devices, game consoles, and set-top boxes. In addition, create a classroom version and provide subscriptions for up to 7,500 disadvantaged classrooms for free.

72 Chronicles of Elyria Video game Kickstarter, Independent Mar 24, 2020 $900k $6,192,308 MMORPG survival game. 

73 Augur Blockchain Ethereum, Independent October 1, 2015 none $5,133,000 An open-source, decentralized prediction market built using Blockchain technology.

74 Restore King Chapel Now. Every Day & Dollar Counts Other Indiegogo May 22, 2015 $8M $5,048,213 Restore Martin Luther King Jr. International Chapel, the only religious building named after Dr. King located at Morehouse College.

75 An Hour of Code for Every Student Other Indiegogo Dec 15, 2014 $5M $5,024,281 Every student in every school should have the opportunity to learn computer science at Code.org.

76 Mastercoin Software Bitcoin, Independent Sep 1, 2013 — $5,000,000 Mastercoin is a digital currency and communications protocol built on the Bitcoin block chain. It is one of several efforts to enable complex financial functions in a cryptocurrency.

This is a list of the highest-funded equity crowdfunding projects.

Rank Project Category Sum Platform Investors notes References

1 BrewDog Brewery ?72,754,050 Proprietary/Crowdcube 117,917  

2 CoinMetro Crypto-Exchange €12,026,735 CoinMetro 7032

3 Paradox Interactive Video game industry $11,800,000 Pepins 2,517  

4 Crowdcube Crowdfunding ?6,565,000+ Crowdcube 3,000  

5 Ameria Advertising €5,000,000 Companisto 2,989  

6 WEISSENHAUS Real estate €7,500,000 Companisto 1,679  

7 Etergo Electric Mobility €3,225,567 Seedrs  

8 Gohenry Finance ?3,999,000 Crowdcube 2209  

9 Chapel Down Group plc Wine ?3,953,819 Seedrs 1,390  

10 JustPark Travel ?3,514,110 Crowdcube 2,702  

11 Sugru Manufacturing ?3,388,150 Crowdcube 2,374  

12 Chilango Food and drink ?3,370,000 Crowdcube 1432  

13 Plant Growth Net Zero Aqualife Shrimp farm $4,575,550 crowdfunder  

14 1Rebel Health and fitness ?2,916,020 Crowdcube 433  

15 Crowdestor Equity Campaign Crowdfunding €1,600,000 Crowdestor 477

16 eMoov Estate agency ?2,622,360 Crowdcube 765  

17 Witt Energy Energy ?2,386,030 Crowdcube 1567  

18 Gritpit Fixings Manufacturing ?4,100,000 Crowdcube 1941  

19 PodPoint Renewable energy ?3,713,450 Crowdcube 1748  

20 Seedrs Crowdfunding ?2,580,000 Seedrs 909  

21 Protonet Hardware €3,000,000 Seedmatch 1,827  

22 Urbanara Home AG Homewares €3,000,000 Bergf?rst ?1,000  

23 Train Alliance AB Real estate $4,400,000 Pepins 600  

24 ingogo Pty Ltd Taxi booking & payments $4,200,000 VentureCrowd 65  

25 Kronf?nster Group AB Retail & manufacturing $3,796,095 Pepins 1232  

26 Hab Housing Limited Real estate ?1,972,560 Crowdcube 640  

27 Parcel Genie Gift delivery ?1,800,000 Angels Den 51  

28 Lovespace Storage ?1,562,960 Crowdcube 257  

29 Hotel Kaiserlei Real estate €2,400,000 Zinsland 1056  

30 Feldbrunnenstrasse Real estate €2,116,200 Exporo 440  

31 Bost?der f?r unga vuxna Real estate €2,111,000 Tessin 179  

32 Companisto Crowdfunding €2,100,000 Companisto 2461  

33 Barista Coffe shop $2,400,000 Pepins 1682  

34 Naava Health Tech $2,368,000 Pepins 1257  

35 UB-Holding Crowdfunding €2,000,000 Rendity 357  

36 Alvestaglass AB Food $1,944,152 Pepins 900  

37 Sion Electric solar car €1,815,000 Seedrs 1,078  

38 Panono Hardware €1,615,745 Companisto 1,804  

39 Freygeist E-Bike €1,500,000 Companisto 1,110  

40 Sawade Food €1,350,000 Companisto 1098  

41 Domaine d?Escapat Wineyard $1,240,540 Pepins 760  

42 Uniti Electric city car €1,227,990 FundedByMe 570  

43 Nordic Oil Cannabis Company €1,167,591 Seedrs 694  

44 Dynamic Code Health tech $1,138,700 Pepins 287  

45 Pickawood Furniture €1,010,000 Seedmatch 795  

46 AoTerra Waste heat recovery €1,000,000 Seedmatch 883  

47 Foodist Food €1,000,000 Companisto 1,980 Exit, 192% ROI  

48 I'll Be Next Door for Christmas Movie $1,070,000 StartEngine and Wefunder 893 First movie to use equity crowdfunding in the U.S.  

The University of Waterloo, located in Waterloo, Ontario, Canada, is a comprehensive public university that was founded in 1957 by Drs. Gerry Hagey and Ira G. Needles. It has grown into an institution of more than 42,000 students, faculty, and staff. The school is notable for being the first accredited university in North America to create a Faculty of Mathematics, which is now the world's largest, and to have the largest cooperative education program in the world. The school is also known for having more companies formed by its faculty, students, and alumni than any other Canadian university, and as such, the university has been called the "MIT of the North". 

The list is drawn from notable faculty, alumni, staff, and former university presidents. The enrollment for 2020 was 36,057 undergraduate and 6,231 graduate students, with 1,350 faculty members and 2,596 staff. About 221,000 people have graduated from the university, and now reside in over 150 countries. 

Alumni and faculty

Fields with a "—" have unknown values.

Alumni

Name Degree Discipline Known for Notes

V. K. Aatre Graduate Electrical engineering Scientist and former head of the Defence Research and Development Organisation  

Michael H. Albert Undergraduate Mathematics Rhodes Scholar, associate professor at University of Otago  

Celeste Anderson Undergraduate Computer Science King of the Nerds winner, competitive gamer  

Gordon Stewart Anderson Undergraduate — Writer  

Mohammad H. Ansari Graduate Physics Fundamental quantum theory research  

Andy Anstett Graduate Politics Ministry of Municipal Affairs  

Paul Antrobus Graduate Psychology Principal at Baptist Theological Seminary, Kakinada (India) and Psychology Professor at University of Regina, Regina, Saskatchewan (Canada)  

Omer Arbel Undergraduate Environmental studies Designer and sculptor and creative director of Bocci  

Karen Autio Undergraduate Mathematics and computer science Writer of children's fiction  

Calvin Ayre Undergraduate Science and Business Bodog founder  

Ricardo Baeza-Yates Graduate Computer science Director of Yahoo! Research labs  

Bill Ballinger Undergraduate Political science Member of the Legislative Assembly of Ontario  

Lisa Feldman Barrett Graduate Psychology Northeastern University professor  

Romesh Batra Graduate Mechanical engineering Virginia Polytechnic Institute and State University professor  

Keith Beavers Undergraduate Kinesiology Competed in swimming at the 2004 Summer Olympics  

Gordon Bell Undergraduate Computer science QNX co-creator  

David Berman Undergraduate Computer science Fellow of the Society of Graphic Designers of Canada  

Peter Besler Undergraduate Chemistry Investment banker  

Art Binkowski Undergraduate Psychology Heavyweight boxer  

Don Boudria Undergraduate Politics Canadian Member of Parliament and Cabinet Minister  

Marie Bountrogianni Undergraduate Arts Member of Ontario Parliament, Minister of Intergovernmental Affairs, and dean of the G. Raymond Chang School of Continuing Education at Ryerson University  

Mark Bourrie Undergraduate History Winner of the RBC Taylor Prize  

Gail Bowen Graduate English Playwright and writer of mystery novels  

Mike Bradley Undergraduate Athletics Canadian Football League running back  

Peter Braid Undergraduate International relations Member of Parliament  

Andrew Brandt Undergraduate Business Former Canadian cabinet minister  

Fiona Brinkman Undergraduate Biochemistry Associate professor at Simon Fraser University  

Alison Brooks Undergraduate Architecture Stirling Prize Award-winning Architect  

Edward Burger Graduate Mathematics Professor at Williams College  

Amanda Burk Undergraduate Fine Arts Artist, associate professor at Nipissing University  

Vitalik Buterin Dropout Computer science Co-founder of Ethereum and as a co-founder of Bitcoin Magazine  

Wayne Cao Undergraduate Computer science Member of the Legislative Assembly of Alberta  

Colin Carrie Undergraduate Politics Member of Parliament  

Jeromy Carriere Undergraduate Computer science Computer architect  

David Cheriton Graduate Mathematics Stanford University professor and Granite Systems co-founder  

V?clav Chv?tal Graduate Mathematics Canada Research Chair in Combinatorial Optimization and former professor at McGill and Stanford  

Ian Clark Graduate Earth science Professor in the Department of Earth Sciences at the University of Ottawa  

George Elliott Clarke Undergraduate Entertainment Poet and playwright; Governor General's Award for poetry recipient  

Rod Coutts Undergraduate Electrical Engineering Founder of Teklogix; namesake of the Rod Coutts Engineering Lecture Building at University of Waterloo  

Clifford Cunningham Undergraduate Physics & Classical studies Astronomer  

Julie E. Czerneda Undergraduate Literature Science fiction and fantasy author  

Heather Dale Undergraduate Entertainment Celtic singer  

Liane Davey Graduate Industrial/Organizational Psychology Leadership consultant, public speaker, and New York Times bestselling author  

Erik Demaine Graduate Computer science Youngest professor ever at MIT  

Dan Dodge Undergraduate Computer science QNX co-creator  

Andrew Drummond Undergraduate Arts Frances Hodgkins Fellow  

Richard Ducharme Undergraduate Civil engineering General Manager of Transportation for Edmonton  

Tom Duff Undergraduate Computer science Computer scientist  

Garfield Dunlop Undergraduate Politics Member of the Legislative Assembly of Ontario  

Fred Eisenberger Undergraduate — Politician  

Jon Evans Undergraduate Engineering Arthur Ellis Awards winner  

Anne Fleming Undergraduate English Fiction writer  

Joe Fontana Undergraduate Chemistry Member of Parliament  

John Friedlander Graduate Mathematics Fellow of the Royal Society of Canada and American Mathematical Society and winner of the CRM-Fields-PIMS prize  

Curwin Friesen Undergraduate Economics Chief executive officer of Friesens  

James Alan Gardner Graduate Mathematics Science fiction author  

J. Alan George Graduate Computer science Dean of the University of Waterloo Faculty of Mathematics  

Garth A. Gibson Undergraduate Computer Science Computer scientist at Carnegie Mellon University  

Brad Goddard Undergraduate Theatre Actor  

W. G. Godfrey Graduate Canadian history Canadian historian  

Gaston Gonnet Graduate Computer science Computer scientist and entrepreneur  

Gary Goodyear Undergraduate Politics Canadian Member of Parliament  

Rick Green Undergraduate Entertainment Comedian and member of The Frantics  

Chris Hadfield Graduate Mechanical engineering Astronaut  

Fariborz Haghighat Graduate System Design Engineering Professor at the Concordia University  

Ann Hansen Undergraduate — Urban guerrilla  

Dianne Haskett Undergraduate Arts Mayor of London, Ontario  

Deen Hergott Undergraduate — Chess International Master  

Cyd Ho Undergraduate Politics Member of the Legislative Council of Hong Kong  

Glenn Howard Undergraduate Environmental studies Three-time World Curling Champion  

Kimmo Innanen Graduate Mathematics Astronomer and professor

David Johnson Graduate Mathematics Mayor of East York, Ontario  

Rupi Kaur Undergraduate English Poet, illustrator, and author. Best known for her debut book, Milk and Honey  

Humayun Akhtar Khan Undergraduate Business mathematics Commerce Minister of Pakistan  

Arounna Khounnoraj Graduate Fine arts Multi-disciplinary artist, teacher, author and co-founder of Bookhou  

Don Knight Undergraduate Accounting Former member of the Legislative Assembly of Ontario  

Tony Knowles Graduate Physical chemistry President of the British Columbia Institute of Technology  

Michelle Lam Graduate/Undergraduate Accounting Founder and CEO of True & Co., a direct-to-consumer digital intimate apparel brand, headquartered in San Francisco, California.  

William Lawrence Kocay Graduate Mathematics Professor of mathematics  

Mike Lazaridis Undergraduate Electrical engineering Research in Motion founder  

Kevin O'Leary Undergraduate Environmental studies Canadian businessman, author, politician, and television personality  

Serge LeClerc Undergraduate Sociology Co-author of Untwisted  

William C. Leggett Graduate Zoology Principal of Queen's University  

Martha Lenio Undergraduate Mechanical Engineering Commander of the NASA human performance study Hawai‘i Space Exploration Analog and Simulation (HI-SEAS)

Rasmus Lerdorf Undergraduate Systems Design Engineering PHP creator  

David X Li Graduate Actuarial science Pioneer of Gaussian copula pricing models for collateralized debt obligations  

Michael Lysko — Former Canadian Football League commissioner  

Rob MacIsaac Undergraduate Economics Former Mayor of Burlington, Ontario; President of Hamilton Health Sciences  

Manas K. Mandal Graduate Biology Director of the Defence Institute of Psychological Research  

Scott Manning Undergraduate — Stunt pilot and CFL veteran  

Peter Masak Undergraduate Mechanical engineering Glider pilot  

Ingrid Mattson Undergraduate — Islamic Society of North America president  

Konris Maynard Undergraduate — Winner of the Saint Kitts and Nevis National Calypso Show  

E. J. McGuire Graduate Psychology Former director of the NHL Central Scouting Services

David I. McKay Undergraduate Mathematics Current President & CEO of Royal Bank of Canada  

Peter McLaren Undergraduate English literature Critical pedagogy  

Nenad Medi? Undergraduate — Professional poker player  

Stella Meghie Undergraduate — Film director and screenwriter  

James G. Mitchell Undergraduate Computer science Computer scientist  

Parker Mitchell Undergraduate — Engineers Without Borders co-founder  

Faron Moller Graduate Computer science Computer scientist  

David Morrell Undergraduate Arts Novelist for First Blood and the creator of the character John Rambo. The book was later adapted into the 1982 film of the same name  

Michele Mosca Undergraduate Computer science Co-founder of the IQC and the PITP  

Heather Moyse Undergraduate Kinesiology Two-time Olympic gold medalist in bobsleigh. Also represented Canada's national rugby team at both the 2006 and 2010 Women's Rugby World Cup  

Walt Neubrand Undergraduate — Keeper of the Stanley Cup  

Paul van Oorschot Graduate Cryptography Carleton University professor  

Chamath Palihapitiya Undergraduate Electrical engineering Venture capitalist, engineer, SPAC sponsor and the founder and CEO of Social Capital  

Steve Paul-Ambrose Undergraduate Science and Business Poker player  

Cole Pearn Graduate Mechanical engineering NASCAR crew chief  

Jean Poirier Undergraduate Environmental studies Member of the Legislative Assembly of Ontario  

Yuri Quintana Graduate Engineering Chief Division of Clinical Informatics, Beth Israel Deaconess Medical Center and Harvard Medical School  

Karen Redman Undergraduate Politics Canadian Member of Parliament  

William Reeves Undergraduate Entertainment Academy Award recipient for Toy Story  

John Reimer Undergraduate Education Member of Parliament  

Neil Robertson Graduate Mathematics Professor at the Ohio State University  

Robert Rosehart Graduate Engineering President of Wilfrid Laurier University  

George Roter Undergraduate Engineering Co-CEO of Engineers Without Borders (Canada)  

Bimal Kumar Roy Graduate Mathematics Cryptologist  

Sandra Sabatini Graduate English literature Writer  

Khaled Al Sabawi Undergraduate Computer science Canadian entrepreneur and was named "One of the World's Top Energy Entrepreneurs" by Global Post in 2010  

Reihaneh Safavi-Naini Graduate Cryptography University of Wollongong professor  

George Samis Graduate Political science Member of the Legislative Assembly of Ontario  

Liz Sandals Graduate Mathematics Member of Ontario Parliament  

Prem Saran Satsangi Graduate Electrical engineering Spiritual leader of Radhasoami faith, Dayalbagh, Chairman (ACE), Dayalbagh Educational Institute, Ex-Vice-chancellor of Dayalbagh Educational Institute, Dean (Academics) at IIT Delhi, system scientist, physicist  

Jonathan Schaeffer Graduate Researcher Professor at the University of Alberta  

Beckie Scott Undergraduate English Olympic gold medalist, the first Canadian and first North American woman to win an Olympic medal in cross-country skiing. Officer of the Order of Canada and Chair of the World Anti-Doping Agency  

Jonathan Seet Undergraduate Singer-songwriter Released albums Melatonin and Arousal Disasters  

Hersh Shefrin Graduate Mathematics Behavioral finance  

Ron Sider Undergraduate Theology Founder of Evangelicals for Social Action  

Bruce Smith Undergraduate Arts Member of the Legislative Assembly of Ontario  

James K. A. Smith Undergraduate Philosophy Associate professor of philosophy at Calvin College  

Steve Smith Undergraduate Entertainment Actor in The Red Green Show  

Moustafa Aly Soliman Graduate Chemical Engineering Pioneered the use of sulfur compounds in thermochemical cycles for hydrogen production & the use of nano-palladium to catalyze partial oxidation of ethane to acetic acid  

Kevin Strain Graduate/Undergraduate Accounting President & CEO of Sun Life Financial.  

Thomas Strothotte Graduate Computer science Rector of the University of Rostock  

John Sullivan Undergraduate — Canadian Football League player  

Vahid Tarokh Graduate Engineering Professor at Harvard University  

Andrew Telegdi Undergraduate Politics Canadian Member of Parliament  

Brad Templeton Undergraduate Software Software engineer and entrepreneur  

Carsten Thomassen Graduate Mathematics Professor of graph theory at the Technical University of Denmark  

Susan Tighe Graduate Civil engineering Canada Research Chair in Sustainable Pavement and Infrastructure Management

Claire J. Tomlin Undergraduate Science Researcher  

Disguised Toast Graduate Computer Science/Mathematics Gamer/Influencer  

Douglas N. Walton Undergraduate Arts Author on argumentation, logical fallacies, and informal logic  

Judy Wasylycia-Leis Undergraduate Political science Manitoba cabinet minister  

Elizabeth Weir Undergraduate Political science Leader of the New Brunswick New Democratic Party  

David A. Weitz Undergraduate Physics Mallinckrodt Professor of Physics & Applied Physics and professor of Systems Biology at Harvard University and director of the Harvard Materials Research Science & Engineering Center

Chris Williams Undergraduate Fine arts Animator, film director, screenwriter, and voice actor  

Jeff Wincott Undergraduate Kinesiology Actor and athlete  

Elizabeth Witmer Graduate Politics Member of Ontario provincial parliament  

Alexander Wong Graduate/Undergraduate Computer Science Scientist  

Bob Wong Undergraduate Science Member of the Legislative Assembly of Ontario  

Steven Woods Graduate/Undergraduate Mathematics Founder of Quack.com  

Ardeth Wood Graduate Philosophy Died in a forcible drowning, and the two-year search for her killer was one of the largest manhunts in Canada  

John Wynne Undergraduate Sports Ice hockey defenceman  

Tim Wynne-Jones Undergraduate Literature Author of children's literature  

Fangjin Yang Undergraduate Electrical engineering Co-founder and CEO of Imply; co-creator of Druid  

Catalina Yue Undergraduate Arts Miss Universe Canada  

Matei Zaharia Undergraduate Computer science Co-founder and CTO of Databricks, creator of Apache Spark, and co-creator of Apache Mesos  

Faculty

Mark Tilden, robotics researcher

Name Relationship Discipline Known for Notes

Gordon Agnew Professor Cryptography Professor  

George Alfred Barnard Lecturer Mathematics Statistics and quality control  

Walter Benz Professor Mathematics Geometer  

Vijay Bhargava Professor Electrical engineering Professor at the University of British Columbia  

Jonathan Borwein Researcher Mathematics Mathematics researcher  

Phelim Boyle Chairman — J Page R Wadsworth chairman at the University of Waterloo  

Tim Bray Manager — Software developer and entrepreneur  

Thomas Brzustowski Professor Mechanical engineering Engineer, academic, and civil servant  

Arthur Carty Professor Chemistry National Science Advisor to the Government of Canada  

Ken Coates Dean History Dean of the Faculty of Arts  

C. B. Collins Professor Mathematics Professor at the University of Texas at Dallas  

Gordon Cormack Professor Computer science Dynamic Markov Compression co-creator  

David G. Cory Professor Chemistry Canada Excellence Research Chair in Quantum Information Processing  

Douglas E. Cowan Professor Religious studies Professor at the University of Waterloo  

Purdy Crawford Governor — Governor of the University of Waterloo  

Paul H. Cress Lecturer Computer science WATFIV creator  

Kenneth Davidson Professor Mathematics Fields Institute director  

Jon Dellandrea Professor Literature Pro-Vice-Chancellor at the University of Oxford  

Jack Edmonds Professor Mathematics Mathematician  

Mohamed Elmasry Professor Engineering Writer for The Globe and Mail  

John R. English Professor Politics Liberal Member of Parliament for Kitchener  

Carla Fehr Professor Philosophy

Eugene Forsey Professor History Member of the Canadian Senate  

Bertram Fraser-Reid Professor Chemistry 2007 Musgrave gold medal winner from the Institute of Jamaica  

Keith Geddes Professor Mathematics Maple co-creator  

Ian Goldberg Professor Cryptography Radialpoint chief scientist  

Ian Goulden Dean Mathematics Dean of the Faculty of Mathematics  

Art Green Professor Arts Professor at the University of Waterloo  

Richard Gwyn Chancellor — Chancellor of St. Jerome's University at the University of Waterloo  

Peter L. Hammer Professor Mathematics Operations research and applied discrete mathematics  

Hiroshi Haruki Professor Mathematics Mathematician  

Geraldine Heaney Coach — Head coach for the University of Waterloo women's hockey team  

Ric Holt Professor Computer science Turing creator  

Thomas Homer-Dixon Professor Environmental studies Professor at the University of Waterloo  

Harold Horwood Writer — Novelist and non-fiction writer  

David M. Jackson Professor Mathematics Professor of combinatorics and optimization  

James Jupp Professor Political science Political scientist and author  

James J. Kay Associate professor Ecology Associate professor of environment and research studies  

Bryce Kendrick Assistant professor Biology Assistant professor at the University of Waterloo  

Murray S. Klamkin Professor Mathematics Mathematician  

Tuffy Knight Coach — Football coach at the University of Waterloo  

Neal Koblitz Professor Cryptography Professor at the University of Washington  

Maurice Kugler Professor Anthropology Social anthropology  

Ziva Kunda Professor Arts Psychologist  

Anita Layton Professor Applied Mathematics Researcher and professor  

Anthony James Leggett Researcher Physics Physics professor at the University of Illinois at Urbana–Champaign  

Melvin J. Lerner Professor Psychology Just-world phenomenon -

Robert J. LeRoy Professor Chemistry Chemist  

Kenneth D. Mackenzie Professor Mathematics Author of Organizational Hologram  

Lorenzo Magnani Researcher Philosophy Philosopher  

Charles Malik Lecturer Philosophy Diplomat  

Lee Maracle Professor Canadian culture First Nations poet and author  

Fotini Markopoulou-Kalamara Professor Physics Theoretical physicist  

Alfred Menezes Professor Cryptography Certicom research associate, MQV co-inventor  

Wendy Mitchinson Chairman History Canada Research Chair in gender history and medicine history  

John Moffat Professor Physics Professor emeritus at the University of Toronto  

Bruce Muirhead Professor Arts Historian  

Robert Mundell Chairman Economics Nobel laureate in economics (1999), known for the Mundell–Fleming model. Was the Chairman of the Department of Economics at the University of Waterloo from 1972 to 1974  

Barton Myers Professor Architecture President of Barton Myers Associates